April 2012 $6.80 ÂŁ4.16 â‚Ź5.00
Maintenance of Wind Turbines 55-57
Online Condition Monitoring
Maintenance Best Practice
Maintec Show Review
Online Condition Monitoring
Maintenance of Wind Turbines
Publisher Michael Dominguez
Editorial editors/contributing: Jon Barret, Christer Idhammar, Alan France
Advertising Paul Clappison - Magazine Paul Miles - Online Advertising Brian Simpson - Direct Marketing
Production Tom Britten
Phone tel: +44(0)1634 731646 Fax: +44(0)1634 731646
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FLEXIBLE CRYOGENIC INSULATION SUITABLE FOR TEMPERATURES FROM -200°C TO +125°C Specialist thermal insulation manufacturer Armacell is launching what claims to be an industry first with a low density thermal elastomeric foam insulation product which retains flexibility even at extreme cryogenic temperatures of 200°C.
AUMA gearboxes support world’s largest hydraulic scheme
Cryogenic processes which utilise such low temperatures and require technical thermal insulation materials include the freeze drying of foods, metal alloy production utilising liquid nitrogen, and the manufacture of some pharmaceutical and chemical products. An area of growing significance is the freezing of large volumes of natural gas down to condensation temperatures (-162°C), with the resultant liquid gas then having a reduced volume of less than 0.17% of the gaseous product. The costs of both storage and transportation of natural gas in a liquid form (LNG) are therefore considerably reduced. Armacell high performance insulation systems maintain the cryotechnical validity of this process throughout, from initial production to final regasification where the gas is fed into pipework for eventual distribution to consumer markets. Armacell have an established reputation for the supply of consistent, high-quality engineered foam materials. This includes-NBR (nitrile butadiene rubber) insulation products, suitable for refrigeration applications operating at temperatures down to -50°C. With the introduction of their cryogenic elastomeric insulation product range, known as Armaflex LTD, temperatures as low as -200°C can now be accommodated. This same product also has an upper temperature thermal limit of +125°C, which ensures that internal surfaces of pipework, tanks and vessels can be safely subject to steam or high temperature chemical cleaning without detriment to the insulation materials. The Armaflex LTD cryogenic insulation materials utilise a completely new diene terpolymer where a much lower glass transition point has been achieved. This is the point (-50°C), where the mechanical behaviour of conventional NBR materials changes, with the rubber increasingly losing flexibility through hardening. However, the Armaflex LTD products maintain full strength and flexibility over the temperature range of -200°C to +125°C. This ensures that vibration and impacts can be absorbed, with the risk of cracking from extreme temperature cycling or mechanical strain considerably reduced. The closed cell material has a very low thermal conductivity and also a high resistance to water vapour transmission providing a ‘built-in’ vapour barrier. These Further information is available on request: Armacell UK Ltd, Mars Street, Oldham, Lancashire OL9 6LY Telephone: 0161 287 7040 Fax: 0161 633 2685 e-mail: email@example.com www.armacell.com/uk
characteristics reduce the risk of corrosion under insulation (CUI), providing significant savings on installation, while the cryogenic foams, unlike rigid foams, also eliminate the need for expansion joints or additional vapour barriers to achieve even further installation savings. Where there is a requirement for sound attenuation, then Armacell’s ArmaSound insulation can also be incorporated as part of a multi-layer thermal - acoustic system to achieve a cost effective result. The innermost layer of the Armacell LTD insulation is fabricated with an outer reinforced-foil anti-abrasive layer. This provides added surface strength as well as enhanced protection from severe vibration and pipework movements. Armaflex LTD products are supplied in preformed tubes of 2 metres in length. These provide a standard 25mm thick insulation cover available in ten standard pipework sizes from 18 to 114mm outside diameter. For tanks, vessels, pipework bends or junctions and intermediate valves etc, Armaflex LTD is also available in continuous sheets or covering rolls to provide tailored sizes to suit the specific installation requirements. Continuous rolls are 1 metre wide x 4 metres long, while covering rolls are available as a 25m2 sheet. For maximum effectiveness and protection against mechanical damage, it is recommended that all insulated pipework and equipment is fitted with a final outer layer of contoured stainless steel sheeting or Armacell’s Arma-Chek R cladding material. The first major application of Armaflex LTD cryogenic insulation materials was for China’s prestigious LNG dock and terminal located in Nianyu Bay at the coast of Dalian City, Liaoning Province. Tankers up to a capacity of 200,000 m3 can be accommodated, and in the first phase completed at the end of 2011, 3 million tonnes of LNG are being converted into 4.2 billion m3 of natural gas annually. The Armacell high performance cryotechnical process has been successfully utilised on vaporisation pipes, pumps, valves and other fittings, to ensure that energy losses during the liquidation, storage and regasification processes are maintained at as low a level as possible.
AUMA gearboxes have been selected to support the world’s largest hydraulic project. By mid 2012, one million people in the metropolitan region of Caracas in Venezuela will benefit from water flowing at a rate of 21,000 litres per second through 72km of pipes. Bespoke AUMA gearboxes, designed for pressures of up to 60 bars, support the giant scale of the scheme. The GS 630.3 gearbox selected for the Venezuelan contract is a highly specialist AUMA product designed for torques up to 675,000 Nm. Built to order, the gearbox is installed in major water installations around the globe including giant subterranean aquifers in the Sahara desert and large scale water supply projects. Located in Miranda, South of Caracas, the scheme – which is known as Tuy System IV – features pipelines up to three metres in diameter. Inauguration of the work is scheduled for June 2012: water will then be transported to people living and working in Caracas, Miranda and Vargas states. The project represents a total investment of $382.3 million by the Bolivarian Government. For over forty years, AUMA has supplied modular electric actuators and gearboxes to major international water projects. With dedicated manufacturing facilities at its German headquarters, a strong engineering focus and expert development team, strength is offered in tailoring products to support the demands of individual projects, such as the contract in Caracas. AUMA – The global supplier of modular electric actuation solutions AUMA Riester GmbH & Co. KG www.auma.com Headquarters address: Aumastr 1 79379 Muellheim, Germany Tel: + 49 7631 809-0
Low emissions at 111 year-old Golf Clubhouse
Atlantic Boilers of Lancashire have supplied three new VF 100kW condensing gas boilers at Formby Golf Course, Merseyside. The Clubhouse was built in 1901 and offers quality accommodation to visiting golfers and members. The Club will stage the “Brabazon Amateur Trophy” in June 2013 and the Clubhouse is receiving an upgrade in preparation for the event. The boilers are stainless steel throughout, and contain low NOX pre-mix modulating burners plus a built-in circulating pump. The control panel includes a management system. The VF system was installed by Strong Maintenance of Knowsley and recommended by Rodney Environmental of Liverpool. There
are four models min the range with outputs from 40kW to 100kW. The VF boilers form part of a flexible, compact system and they are suitable for many types of building. For more information see www.atlanticboilers.com, email: firstname.lastname@example.org or call 0161 621 5960 for technical advice.
New Stocked Tension/Compression Load Cells from LCM Systems Means Lower Prices and Faster Delivery
Spirax Sarco advises on flowmeter selection in new White Paper Spirax Sarco has published a new White Paper providing steam users with top tips to correctly select the right flowmeter to achieve targeted energy savings. The White Paper highlights the importance of monitoring and targeting schemes in light of carbon emissions legislation and volatile fuel prices, and how accurate steam measurement is key to improving plant efficiency, energy efficiency, process control and costing. The steam metering White Paper presents the technical differences in measuring steam compared to other fluid flowmetering, and what variables, such as temperature or pressure, should be considered to ensure an accurate reading. Other considerations included in the document are erosion; velocity; installation space; flowmeter turndown; and accuracy. The mainstream flowmeter types and their suitability for
accurate steam measurement is a main feature of the White Paper, presenting benefits that include the best turndown ratio, accuracy and cost. Over eight flowmeter varieties are evaluated and brought together in an easy-toread comparison table. For a copy please visit www.spiraxsarco.com/uk, alternatively email uk.enquiries@ uk.spiraxsarco.com or call 01242 535319, ref: ‘Steam Metering White Paper’.
Norbar Moves To Expand
With another record year for load cell solutions provider, LCM Systems, a new initiative has been introduced that means lower prices and faster delivery for all customers. The company is pleased to announce that its best selling DCE load cell for measurement of tensile and compressive forces is now available ex-stock from its headquarters on the Isle of Wight. This small and versatile product is ideal for design engineers and systems integrators who are working on applications for tensile strength, tension measurement and general force applications. The standard product is offered in ranges from 100N to 50kN, although specials can be designed and manufactured not only with customised ranges, but different thread sizes, integral connectors and high temperature versions are all popular requests from design engineers. This compact load cell is constructed in stainless steel and environmentally sealed to IP65. To add to its versatility, different mounting options are available, designed to make the load cell suitable where space is limited and a version with rationalised output can also be supplied. Over the past six months, LCM Systems has extended its factory by 30%, allowing parts to be held in stock for even faster assembly and delivery. As well as the DCE load cell, in future, customers will be able to order shackle load cells, the SGA analogue stain gauge amplifier and the TR150 handheld load indicator for immediate dispatch.
Norbar Torque Tools is to move to a new 170,000 square feet production site, over three times larger than its existing factory. This is to expand manufacturing output and so deal with increased demand for its precision engineering products, 75% of which are exported worldwide to over 100 countries. The company is remaining in Banbury, Oxfordshire, where it has been established since its launch in the 1940s, demonstrating continuing commitment to the town and its workforce, most of whom live locally. Norbar plans to increase its current 240-strong workforce by up to 30 new employees this year and further recruitment is planned as the changeover gathers pace. In June 2012, a quarter of Norbar’s workforce will move to the new factory in Wildmere Road, about 1.5 miles from its current premises, with torque wrench assembly being the first production team to relocate. This will create more space within the current factory for the installation of more machine tools used in the production of Norbar Pneutorque® and Handtorque™ torque multipliers. For further information about Norbar products and services, contact: Norbar Torque Tools Ltd, Beaumont Road, Banbury, Oxfordshire, UK OX16 1XJ T+44 (0)1295 270333 email@example.com
New Range Of Air Compressors Launched By FPS Use of advanced techniques delivers permanent energy savings A new range of variable-speed air compressors from FPS Compressors is claimed to represent a significant step in maximising energy efficiency. Called the Galileo range and manufactured by Power System Group, the new machines differ from standard variable speed compressors by using direct drive, permanent magnet motors
and sophisticated controls to bring significant gains in energy efficiency. Normal variable speed compressors are fitted with an asynchronous or induction type electric motor that is usually paired with a frequency controller or inverter. This arrangement can be very useful in saving power when compared to the on/off regulated compressors which are still in frequent use. This well-known arrangement however, whilst being a step forward from older technology, is less energy efficient during periods of low demand and very high demand. During low demand the speed of the
motor is reduced and at low speed the induction motor becomes less efficient. When demand is at its highest the energy losses in the inverter also penalise efficiency. The new Galileo compressors are based on the proven PS-DV Series platform of variable-speed compressor with highly efficient compressor air end, direct drive and sophisticated controls. The adoption of a new generation permanent magnet motor however brings further gains in energy efficiency to what are already very efficient machines. The specially designed synchronous motor, using permanent magnets, provides several benefits over asynchronous motors. These include the avoidance of extra field current normally required to generate the magnetic field in the rotor, very high flux density, high and constant torque, higher power factor and efficiency across a very wide range of operating speeds. These factors make Galileo
models highly efficient, delivering further savings of around 9-12% when compared to other variable speed compressors. Sophisticated controls include the capability of connecting to external control, monitoring or visualisation software or even business management applications via a LAN, serial interface or web-connected modem. This allows remote computer based monitoring and diagnostics functions to be implemented, making this one of the most technically advanced energy saving variable speed air compressors available. There are over 25 models in the Galileo range, offering a wide range of performance, from 9 kW to 180 kW with operating pressures between 7.5 bar and 13 bar and with capacity from 1570 L/min to 30,000 L/min. Further Information: FPS Air Compressors Ltd Rycote Lane Thame Oxon OX9 2JS Tel: 01844 212233 Fax: 01844 212620 Email: firstname.lastname@example.org Web: www.fps-compressors.co.uk
Monitor Indoor Air Quality (IAQ) with PPM Technology PPM Technology, a specialist gas detection and indoor air quality instrumentation manufacturer from Wales has developed a range of multi-parameter indoor air quality monitoring equipment. In order to accurately understand a building’s indoor air quality, it is advised to simultaneously monitor various indoor air quality parameters including gases, temperature and humidity in various locations throughout the building. PPM Technology’s range of Indoor Air Quality (IAQ) monitoring instruments include the Wireless IAQ Profile Monitor it can contain sensors for a maximum of 7 customer specified IAQ parameters. A compact model is also available - the Mini IAQ Profile Monitor can contain a maximum of 5 sensors. Both these instruments send the collected IAQ data wirelessly to the control pc/laptop in real-time; a large number of units can be networked together to enable accurate monitoring of an entire building. The PPMonitor software enables the data to be viewed graphically, produce reports and statistical data, run schedules as well as alarm functions and notifications for more effective and economical building management. Our latest instrument the ‘Touch Screen’ IAQ Profile Monitor is a stand-alone IAQ monitoring unit, capable of continuously monitoring up to 7 IAQ parameters. It is built with an integrated ‘touch screen’ panel, which allows the user to navigate through the various sensors simply by touching the screen.
Please visit www.ppmtechnology.com for more information. email@example.com PPM Technology Unit 34, Cibyn Industrial Estate Caernarfon, Gwynedd. Wales, UK. LL55 2BD Tel: +44 (0) 1286 676 999 Fax: +44 (0) 1286 676 811
Virtually Pulse-Less Flow Removes The Need For Pulsation Dampeners The unique multi-diaphragm arrangement of the HydraCell metering & dosing pump is claimed to remove the need for pulsation dampeners in many circumstances. Pulsation in a hydraulic system is invariably caused by the pump specifically, a reciprocating, positive displacement pump. This type of pump generates its motive force by importing and expelling a predetermined volume of liquid with marked regularity, causing rapid acceleration and deceleration
of the fluid. Pulsation is usually observed as noisy vibration in system components or rapid gauge fluctuation but can be influenced by the harmonics of individual components within the system. This vibration can be a major problem, potentially causing component failure through fatigue or simply leakage in discharge pipe work due to pipe strain. Hydra-Cell pumps from Wanner have multiple, hydraulically balanced diaphragms that operate sequentially,
dramatically reducing system pulsation and damage it causes. The cost of additional pulsation dampeners is avoided in many instances and systems become more reliable. The Hydra-Cell pump range can accommodate measured flow requirements up to 170 litres per minute at pressures of up to 207 bar. Hydra-Cell pumps also exceed API 675 performance requirements in terms of repeatability, linearity and steady state accuracy, and are able to pump abrasives and liquids that contain solid particles reliably
due to its unique horizontal check valves and can even run dry indefinitely without suffering damage.
James Walker investment cuts manufacturing lead times The successful development of new production processes, plus continued investment in new people and plant, has allowed sealing solutions provider James Walker to make significant reductions in manufacturing leads times across a growing number of the company’s range of static, rotary, hydraulic and custom-moulded sealing products. Over 500 lines of high performance ‘O’ rings are now available ex-stock, including items manufactured in the company’s industry-leading rapid gas decompression resistant materials. Achieved against a background of rapidly rising demand, the expansion of the stocked ranges has created capacity on the production floor which has allowed ‘make to order’ times to be reduced by nearly 50%.
Similar lead time improvements have also been made on the James Walker Springsele range, again including versions manufactured in highperformance RGD materials. The latest plant to be installed represents the third significant investment package to be put in place at the company’s Cockermouth manufacturing facility in the last 12
Denso Void Filler Aids Corrosion Prevention at Aberdeen Harbour
Aberdeen Harbour Board has recently completed the redevelopment of shipping berths at Torry Quay to meet the requirements of larger supply ships for the North Sea oilfields. The main contractor was McLaughlin & Harvey from Belfast.. An integral part of the quay construction is formed by ten metre horizontal tie-bars which are cast into a structural concrete slab located four metres below the finished surface. The bars protrude through the main quay wall formed by sheet piles and act as a fundamental component of the structure, thus requiring protection from the harshest
marine conditions. In order to deter corrosion and help elongate the structures life span it was a design requirement to conceal the exposed ends within steel cylinder caps and provide an anti-corrosion void filler compatible with the cathodic protection system. McLaughlin & Harvey sourced Winn & Coales (Denso) Ltd’s Denso Void Filler from local stockists, SIG Construction Products of Perth, and acquired approval by the consultant designers Arch Henderson for use. Winn & Coales Denso Void Filler is based on a microcrystalline petrolatum containing corrosion inhibitors and moisture repellents. It forms a permanently flexible medium for the encapsulation and protection of bearings, tendons, stay cables, etc. It has been used on a variety of major civil engineering projects, including both Severn Bridges.
months in addition to increases in staff levels. The investment has been aimed at extending the facility’s flexibility in addition to meeting a growing global demand across the range of products manufactured by James Walker & Co. The latest lead time improvements are in addition to the company’s existing Xpress priority manufacture and dispatch services www.jameswalker. biz/xpress which cover Walkersele® rotary seals, including on-site joined (OSJ®) versions, plus Chevron® and Solosele® hydraulic seals.
Full details of products available on priority manufacture and dispatch are available from the James Walker & Co sales team on 01270 536 000.
Arjowiggins extends Cofely’s CHP management contract Cofely, a GDF SUEZ company, has signed a 5 year contract extension with Arjowiggins Paper Group to provide energy and utilities management for the CHP energy centre at the company’s manufacturing facility at Chartham Mill, Kent. The contract extension builds on a long term relationship, since 1993, that has seen Cofely implement a management programme to reduce energy consumption and carbon emissions. Cofely has developed a specialist operational model
to ensure the energy centre runs at maximum efficiency against multiple energyrelated scenarios. Plant configuration is optimised after analysis of electricity import/export prices, gas price, and site electrical and thermal demands. For further information, visit www.cofely.co.uk
Operations & Maintenance
Operations + Maintenance = Production Reliability and Maintenance Management Consultant Idhammar is vice president of IDCON, Raleigh, NC, a reliability and maintenance management consulting firm, specializing in education, training and implementation of improved operations, reliability, and maintenance management practices. Feedback on this reliability article is appreciated. Send to firstname.lastname@example.org For plant maintenance consulting information. Please call (919) 847 8764. From my experience, it is more common than not to find that the working relationship between operations and maintenance is one of adversity instead of a relationship of close and productive cooperation. Operations often sees itself as the customer of maintenance, and, consequently, maintenance is viewed as a service provider. In such a relationship, it should be obvious that operations is responsible for the cost of the maintenance work it requests and gets delivered. However, in a bad relationship, this is not the case. As long as maintenance work requests are performed, operations views maintenance as the good guys. But, if at the end of the year it shows that the maintenance budget is exceeded, it is not unusual to find the maintenance manager in the hot seat having to explain why more money than budgeted was spent. In a customer/service-supplier relationship, it is also common to find that priorities are very emotional. The customer wants something done and the service supplier says “yes, sir” and does its best to deliver. This is often done even if the service supplier knows that there is more important work to do instead of the work it was requested to do. I could go on with many other issues that result from this type of relationship, including lack of trust, poor communication, and finger pointing when problems occur, etc. However, I will instead focus on what you should do to improve this relationship. AGREE ON THE SAME GOAL. Ask yourself what the business of maintenance is and what the business of operations is. We could have a lengthy discussion around this, but common sense dictates one conclusion: If you manufacture pulp or paper, your common goal must be that both departments are equal partners in manufacturing your product in the most cost effective manner. This soon comes down to the following formula: Time Efficiency x Quality Performance x Speed Performance, which is often called Overall Equipment Efficiency (OEE) However, I suggest you change the name to Overall Production Efficiency (OPE).
Why? Because you need to express clearly that both departments do have one and the same goal. You will no longer talk about lost production by departments in a finger-pointing manner. Instead, your focus should be root cause problem elimination. This is an important change, since it is not enough to just say, “Okay, from now on we are partners instead of customer/suppliers.” Next, you make friends and do some teamwork training, etc. You must also change the way your processes work. To change from OEE to OPE means that you also must abandon the practice of categorizing lost production by department—for example, by mechanical, electrical, instrumentation, and operations. If you still do your production reports this way (which 95% of the industry in fact does), you break a ground rule when you try to get people to work together by asking “who?” instead of “why?”. I suggest you instead implement the following process: 1. Collect problems that have caused high costs in safety, environmental, lost production (quality, time, speed), or problems causing high maintenance costs. 2. Select which problem(s) to solve. 3. Assign a problem owner to the selected problem. 4. Problem owner selects a team to help solve the problem. 5. Solve the problem. 6. Document the solution. 7. Educate the rest of the organization in the solution. If you truly did more of the above, instead of wasting energy and time on guessing which department is to blame, you would have started autonomous education and training. You will also remove one of the barriers that keep you from working better together. Soon, you will also see that problems are not always classifiable by department, because the root cause to the problem is often a mix of how you operate the equipment and/or the process and how you maintain it.
ESTABLISH THE RIGHT FOCUS. If you agree with the ideas presented in the August column—that the relationship between operations and maintenance should be a partnership, not a customer/ supplier relationship—the next step in promoting this partnership is to establish the right focus in your joint improvement effort. So, if maintenance is not a service provider, what does maintenance deliver? I think that both maintenance and operations deliver reliability. The maintenance department delivers equipment reliability and the operations department delivers process reliability. Reliability can be defined as “Quality production output at expected speed without downtime, personal injuries, or environmental damages,” or the same as OPE or overall production efficiency (see August column). It can be measured as OPE or with the following formula: MTBPL/MPL, where MTBPL = mean time between production loss and MPL = mean production loss. The term “production loss” is suggested rather than the more common reliability term “MTBF” (mean time between failures). The reason for this is that you should stress the fact that you want to avoid operational problems, as well as equipment problems. The term “failure” is too often related to technical equipment failures (maintenance). If you have decided to focus your improvement efforts on reliability improvements that will result in sustainable, lower maintenance costs, I advise you to find out the revenue of increased reliability as it compares to the value of reducing maintenance costs. A common way of doing this is to estimate the average market price for a product or a product mix over the last five years. Then, deduct the variable cost to make the product over the same time period. For example: a pulp mill received an average market price of $700/ton for its product mix. The variable cost to make a ton was $340. The financial contribution the mill will receive for each ton made and sold is consequently $360 per ton.
Operations & Maintenance
graph, your joint goal is to continuously increase MTBPL and decrease MPL. The combined results of this will be a reliability factor of, for example, 50.4. Your joint operations/maintenance goal is to continuously increase this factor.
• • • •
reliability. There is revenue as a result of improved reliability. Improved reliability results in lower sustainable maintenance costs. Solve problems-do not classify production losses by department. All of the above were explained in the August and October columns. Other things you can do to promote the partnership are: Include operators in basic inspections and essential care of equipment Agree on guidelines for priorities of work requests Communicate production plans Create a joint shutdown schedule
Of course, the most important part of building the partnership is personal relationships. However, organizations are changing, and, with the wrong processes in place to promote a partnership, things will fall back to a less effective work system.
As shown in the graph, your joint goal is to continuously increase MTBPL and decrease MPL. The combined results of this will be a INCLUDE OPERATORS. reliability factor of, for example, 50.4. Your joint operations/maintenance goal is to Where it is practical and makes sense, continuously increase this factor. operators should undertake some basic inspections of equipment. If it is practical The next thing you need to do is to identify for an operator to do inspections, they the bottleneck of the process line making should be taught to do so. As a guideline-if the product and the OPE of this process. If an operator can be trained in an inspection the bottleneck is the bleach plant and the method in less than 15 minutes, he or she OPE there is 84%, the potential opportunity should be trained to do that inspection. to increase OPE is most probably in the area of 6% to 10 %. Assuming that the pulp A classic example is the inspection of a dryer machines and baling lines can handle rotary steam joint for a paper machine. It the increase in production and your present makes sense for a back tender to not only throughput is 500,000 tpy, the value of a look at ropes, felts, paper web, doctor 5% increase in production throughput is blades, condensate returning through worth 25,000 tons x $360 = $9,000,000/ steam joint, etc., on the back side of a year. The maintenance cost for this pulp mill paper machine, but to also inspect the is $87/ton or a total of $43,500,000/year. A condition of the carbon ring in the steam 5% reduction in maintenance costs would joint. Training operators on how to do this be worth $2,175,000/year, or 24% of the takes less than five minutes. value of increased and sold production. In this example, it should be obvious that your joint operations/maintenance focus should be reliability. A lower maintenance cost will then follow as your reliability increases. The problem is that your boss might ask you to do both at the same time, or even worse, ask you to first cut the maintenance cost and then focus on reliability. My experience has shown over and over again that this approach will fail.
As can be seen in the picture, a pin on the side of the joint housing is indicating the wear of the carbon ring inside the joint. Where there is less than a 1/8-in. distance between the housing and the locker ring on the pin, the carbon ring needs to be replaced in the next shutdown. With a good light source, an operator can check about five joints in each direction when he or she is doing other operations inspections on the backside of the paper machine. This is a very good and reliable inspection and it is only one example out of many that are logical to train operators to perform. By the way, you might be surprised to know that many very experienced paper makers have never heard of this basic inspection method; they still run joints until they leak and cost 300% to 800% more to repair. maintenance work should start with a work request, not a work order AGREE ON WORK REQUEST PRIORITIES. First of all, maintenance work should start with a work request, not a work order. A work request might or might not turn into a work order. If a work request turns into a work order, the execution should follow jointly agreed upon priorities. It is a very good idea to develop these together between operations and maintenance. To sit down with your operations partner and agree on these guidelines and then start using them jointly is one of the most hands-on and best ways of making the partnership happen. I will be glad to send anybody who requests it an example of a priority guideline. PROMOTING PARTNERSHIPS. To make a partnership between maintenance and operations successful, you need to do things differently than you have done in a customer-supplier relationship. For example, you should: • •
A JOINT VENTURE.
Agree on the same goal-overall production efficiency (OPE). Achieve the right joint focus-total reliability. There is revenue as a result of improved reliability. Improved reliability results in lower sustainable maintenance costs. Solve problems-do not classify production losses by department. Include operators in basic inspections and essential care of equipment. Agree on guidelines for priorities of work requests. If you want a copy of this, please contact me by email.
One thing is to agree to that operations and maintenance are equal partners in a joint venture resulting in reliable production. Another thing is to make it happen, and, to make it happen, you need to do things differently than you have done in a customer-supplier relationship. For example, you should:
All of the above were explained in my previous three columns on this topic. In the four following sections, this column focuses
Agree on the same goal-overall production efficiency (OPE). Achieve the right joint focus-total
Operations & Maintenance on other things you can do to promote the partnership.
OPERATING PRACTICES / MAINTENANCE PREVENTION.
Include operating practices in your maintenance prevention program. When you do the priority guideline jointly with It might seem obvious that communicating production plans is done no less often than operations, you will most probably discuss one event called “critical process running in your weekly Thursday meeting between on spare equipment.” This is when, for the operations and maintenance partners. example, you run a spare pump because However, my experience is that it is not the redundant pump is not performing. a given that maintenance and operations This event often triggers a long discussion. communicate the production plan well Operations has always called maintenance enough. resources to repair the failed pump, even if it is two o’clock in the morning. As a minimum requirement, the production The solution is that switching pumps plan is posted weekly and updated daily. This allows scheduling of maintenance work between shutdowns becomes the responsibility of operations. All doubled to best take advantage of all opportunities pumps are marked “A” and “B,” so it is that present themselves. This is important easy to remember which pumps to run. for a pro-cess producing many different sheet characteristics, such as a paperboard (It is not unusual to find that both pumps are unknowingly running and working machine making everything from uncoated to coated on one or both sides, running one against each other). There are many other operating procedures you should include or more wires. It is also important in other in your maintenance prevention program. processes. For example, if you make one Examples include how to heat up a steam type of pulp in a continuous digester, you system, how to start a pump correctly, and will have fewer maintenance opportunities how to clean without causing problems. on short notice. COMMUNICATE PRODUCTION PLANS.
IDENTIFY MAINTENANCE OPPORTUNITIES. Sit down with your operations partner and identify all maintenance opportunities that present themselves as you go through each product you manufacture. Also, estimate a time range available for maintenance work. Give each maintenance opportunity a code and describe them on the backside of the priority guideline (see December 2000 column). In your work requests, the requestors should fill out the maintenance opportunity as a minimum requirement per your standard for “work re-quests.” The value of doing this is that you will learn more about the manufacturing process, while at the same time promoting the partnership and opening up more opportunities to do maintenance without losing production. You will start taking advantage of all scheduled and unscheduled shutdowns to do necessary maintenance work. JOINT SHUTDOWN SCHEDULE. It is not uncommon to find that there are four to five shutdown schedules, and these schedules are not well connected to each other. There might be one schedule for operations work, another for mechanical work, etc. An indication of a good partnership between operations and maintenance-and also within maintenanceis that there is only one schedule for every shutdown. This schedule should be well connected between all involved departments.
VISION AND MISSION STATEMENTS. As most of us know, vision and mission statements do not always exist, and, if they do exist, they are seldom wellcommunicated or understood. Not long ago, I sat in a meeting to discuss these statements with a group of operations and maintenance managers from a large international company, along with their vice president of manufacturing. After presenting the many different statements used in different plants, it all became very confusing. “Do we all understand the difference between vision and mission?” a frustrated manager asked. It showed that most people in the meeting could not clearly define the difference, yet they all had documented statements. To make a long story short, it was decided that a vision statement should explain what the organization would like to become or where the organization would like to be in the future. On the other hand, a mission statement should explain the purpose of the organization¹s existence. It was also determined that these statements would be decided on a corporate level as a decree. How each organization accomplished the mission was left up to that organization. A long discussion followed on the different roles of production and maintenance, and, at the end, it was determined that production is a partnership not an internal customer relationship and this must be reflected in the vision and mission statements. Nomenclature therefore needed changing so that production became the common denominator for operations and maintenance.
If you read the previous columns, and agreed to the approach, the following should be easy to agree on: • • •
The result of maintenance work is equipment reliability (and preservation/ prolonging life of assets). The result of operations work is process reliability. Together, the result is production reliability.
Consequently, in our meeting, the mission statement for maintenance was agreed to read as, “To deliver cost-effective equipment reliability,” and, for operations, “To deliver cost-effective process reliability.” The term cost-effective means that the cost to accomplish a result must be less than the value the result is expected to deliver in comparison with other investment alternatives. The joint mission statement was decided upon as, “Operations and maintenance shall together deliver costeffective production reliability.” CURRENT BEST PRACTICES DOCUMENT. The vision statement for maintenance is built on what we call current best practices (CBP). Each key process in reliability and maintenance is identified and documented, for example: Leadership and Organization; Planning and Scheduling; Preventive Maintenance; Technical Database; Stores Management; Root Cause Problem Elimination; and so forth. Each of these key processes is broken down into sub-processes. For example, within the key process of Planning and Scheduling is the sub-process of Work Request. This sub-process contains elements such as Scope of Work Defined, Equipment Number Defined, and so forth. The CBP document forms the basis for evaluating the gap between how good an organization is and how good it could be. Based on the agreed upon CBP document, the following vision statement was adopted during our meeting: •
Achieve an average of 80* for all CBP elements by the year 2005.
On a scale of 100 I can assure you that this is an aggressive vision; I have never done an audit that has resulted in higher than 55 on this scale. Achieving the vision will result in increased reliability and, consequently, lower maintenance costs, but it can only be accomplished in a partnership with operations and engineering.
Norbar Scoops Two Major Business Awards Banbury based Norbar Torque Tools has achieved major recognition in the Cherwell Business Awards for 2012, receiving both the ultimate prize as Business of the Year 2012 and the Staff Care and Training Award for the motivation and support of its employees.
Norbar is a family run company and the world’s leading specialist in the design, development and production of torque tightening and measuring equipment. There are Norbar sales companies in Australia, China, India, New Zealand, Singapore and the USA, but manufacturing is carried out solely in Banbury, where Norbar has been established since the 1940s. The Cherwell Business Awards are an important annual celebration of business excellence, organised by Cherwell District Council, the Chambers of Commerce for Banbury and Bicester, Bicester Vision and Spratt Endicott. Sponsors represent a range of key business and professional organisations in this area of North Oxfordshire. For further information about Norbar products and services, contact: Norbar Torque Tools Ltd, Beaumont Road, Banbury, Oxfordshire, UK OX16 1XJ T+44 (0)1295 270333 email@example.com
Supplying Centrifugal Pumps For Over 35 Years Moody Systems are suppliers of new and used equipment to the food, dairy, ice cream, beverage, brewery, pharmachem industries. Moody Systems have been supplying centrifugal pumps for over 35 years. We stock a wide variety of Centrifugal Pumps including:
Alfa Laval LKH Pump
APV Puma Pump
Alfa Laval ALC Pump
APV W + Pump
Please contact Kerry Piper on 01777 712110 or firstname.lastname@example.org You can also visit our stock list at www. moodysystems.co.uk and scroll down the categories list to find ‘Centrifugal Pumps’.
Get Alarmed Before There Is Fire Or Explosion Detect Heat (and Fire) and report/alarm from 60 – 385°C in Engine-rooms, Windmills, Power Plants, Ovens, Generators, Trains, Dryers, Gas turbines, Heating rooms, Factories, Inventories and many more. Reliable 2- or 4-wire N/O or N/C switches, FM approved, connect to your existing alarm system or take the comprehensive LICO HDL & Stand-Alone or intermitting Alarmpanel HDL to secure lifes and your values by “in advance monitoring”. LICO Electronics GmbH Klederinger Str. 31 A-2320 Kledering Austria Tel + 43 1 706 43 00 Fax + 43 1 706 41 31 email: email@example.com
LICO Hungaria Kft Raba u. 4 H-2030 Erd, Hungary Tel + 36 23 520 113 Fax + 36 23 520 115 email: firstname.lastname@example.org
Learn more by visiting: www.lico.at or: www.fenwal-direct.eu LICO Mecatronic S.R.L. Str.Bucinului Nr.2B / 19 RO-540526 Targu-Mures Romania Tel. +40 365 807 497 Fax: +40 365 434 999 Email: email@example.com
Water Mist Generator For Shock Wave Attenuation Water mist generator designed for protecting people from unauthorized explosions in underground structures, oil platforms and methane explosion in coal mines. The new generator activates at the command received from a blast detection wireless system. The activated generator produces a tailored water mist with droplet sizes in the range of 25-400 micron that are discharged along selected sections of a tunnel. The time of activation from the moment of blast is 11 ms, the mist discharge speed is 60-80 m/s, the volume of discharged water mist is 90-100 liters per activated station, and the shock overpressures are decreased by a factor between 1.9 and 2.3.
Left: water mist generator for horizontal dispersal. Above: for vertical dispersal. 1 - absorber control block 2 - high pressure camera 3 - water container 4 - nozzles
Center for Infrastructure Protection and Physical Security (CIPPS), University of Florida, 365 Weil Hall, PO Box 116580, Gainesville, FL 32611-6580, USA (firstname.lastname@example.org)
Page Oil Analysers Header
Kittiwake Launches FTIR3 Oil Analyser First compact, field unit of its type designed to meet ASTM specifications Traditionally lab-based, Fourier Transform Infra Red (FTIR) machines offer an in depth understanding of many oil parameters, quickly and without the use of complicated tests and chemical reagents. FTIR is the predominant Infrared Spectroscopy (IS) methodology, providing information on multiple parameters simultaneously, offering both qualitative and quantitative measurements, which makes it an invaluable source of information for maintenance engineers. Kittiwake’s portable FTIR3 Oil Analyser comprises three main components (FTIR3 spectrometer, portable computer and carrying case), and is simple to operate, requiring only 2 ml of oil sample to produce accurate, reproducible results in minutes. A rapid method of screening oil samples that have problems, the results provide general information about the identity and condition of the oil; for example degradation by-products, additive depletion and contaminants. The FTIR3 Oil Analyser is configured to ASTM D7418 Standard Practice and the included software comes pre-loaded with the complete range of JOAP and ASTM approved methods used for the condition monitoring of inservice lubricants. Also preconfigured are industry-accepted methods under ASTM consideration including: • • • • •
Antioxidant depletion Glycol contamination Water Sulphonation Oxidation
Nitration Phosphate Antiwear
Further test methods can be added as and when they are approved by the standards bodies. The powerful FTIR software provided on the netbook is simple to use. It allows users to set up multiple machines and oil types and also define what parameters are measured on each sample. Data is stored on the machine and can either be viewed numerically or in graphical format for trending over time. Custom alarms can be set for any measured parameters these can be either a simple pass/fail, or warning levels with various levels of severity and colour coding, as defined by the user for the specific application. In addition, spectral data can be viewed graphically and compared with new oil spectra. Martin Lucas, managing director, Kittiwake Group explained: “As equipment operators gain a greater understanding of the benefits of condition monitoring to protect their major assets, the use of on-site, in-service oil analysis is becoming more prevalent. Until now, lab grade instruments have been too bulky or delicate for field use, which is why Kittiwake has developed the FTIR3 Oil Analyser. The first compact, field unit of its type, it is capable of detecting multiple oil analysis parameters simultaneously and providing rapid analysis without the need for extensive sample preparation or wet chemistry. Designed to meet ASTM
specifications, the FTIR3 Oil Analyser assures users that established, trustworthy procedures and operations are employed for best practice and precision.” The launch of the FTIR3 Oil Analyser represents the latest innovation from Kittiwake’s R&D team, following the recent launch of its ATEX and IECEx certified Metallic Wear Debris Sensor, an industry first for Zone 1 ”hazardous” environments. Traditionally used with critical gearboxes, the Metallic Wear Debris Sensor continuously checks on the health of an asset and alerts the user to changing wear patterns. With the addition of ATEX and IECEx certification, the sensor can now be used in hazardous zone 1 and 2 applications where explosive gasses are likely to be present.
http://www.kittiwake.com Kittiwake Developments Ltd. Tel: +44 (0) 1903 731470 Fax:+44 (0) 1903 731480 Email: email@example.com
Spirax Sarco Offers Expertise On New Boiler Guidance Spirax Sarco has launched a new online compliance webpage to help customers with the arrival of both the Guidance on Safe Operation of Boilers (BG01) and Management of Industrial and Hot Water Boilers (INDG436) guidance notes. (www.spiraxsarco.com/uk/bg01) Visitors to the webpage can find out how the new guidance documents differ from the previous best practice and how to bring existing boiler operations up to scratch. Both BG01 and INDG436 are available for download on the webpage, as well full access to a BG01 presentation from Gastec. The two documents present new challenges for boiler managers and operators, including the recommendation of specific boiler
training courses and the review of boiler risk assessments. By adhering to the new advice steam users can now show regulators and insurers that they are committed to the industry’s best practice. “Our extensive experience with steam and condensate systems allows us to offer steam users the best advice on how to remain compliant with the new industrial boiler guidance,” says Paul Mayoh, Spirax Sarco’s Technical and Quality Manager. “These new
documents highlight the importance of boiler safety, but knowing the best ways to operate and maintain a steam system is the key to improving efficiency, boosting productivity and reducing costs.” For the first time, BG01 recommends specific training to promote safe and competent boiler operations. This includes Certified Industrial Boiler Operator (Cert.IBO) status for operators and Diploma in Boiler Plant Operation Management (Dip.BOM) for managers. These are both covered in Spirax Sarco’s Boiler Operation Accreditation Scheme (BOAS) training course, at the new UK Steam Technology Centre in Cheltenham and on-site. Boiler managers are also reminded that any recent changes to personnel levels or control equipment will need a review of existing risk assessments. Spirax Sarco’s experts can support managers in developing their own risk assessments, from the combustion or efficiency side of the boiler house, to accessibility and manning levels.
To find out more about the new boiler guidance and how Spirax Sarco can help you remain compliant with BG01 and INDG436 please visit: www.spiraxsarco.com/uk/bg01 or email: firstname.lastname@example.org
Beko Technologies solves KP Foods’ drying problems. KP Foods, a part of the United Biscuits group have had issues in recent years with refrigeration dryers failing because of the acidic conditions on site due to ingredients such as acetic acid affecting the internal copper tubing of refrigeration dryers. A number of different brands of dryer have been tried and tested on site with limited success. Some dryers actually failed in less than 6 months. BEKO TECHNOLOGIES looked at the PH value of the condensate and the acidic ambient conditions. From this a tailor-made DRYPOINT RA 600 solution was offered, where all the internal copper piping and condensate discharge points of the dryer were coated with a special anti-corrosion treatment. The first RA dryer sold to KP Foods has been installed on site now for nearly 4 years without a single failure. This was a major factor in the choice for the new dryers for the Hoops compressor room location. Pressure drop was also a major factor as well as pipe work distribution. With this in mind BEKO were invited to tender for the whole turnkey project which included removing all the old equipment, supply and installation of new dryers, filters and pipework. BEKO successfully won the order for the complete turnkey project and in conjunction with Direct Air and Pipework of Coventry the whole installation was carried out in less than 48 hours. The installation included a complete new 6” manifold, 4” drops into the 2 x DRYPOINT RA 600 dryers and 2 x Flanged filters. Timing was essential as the compressed air went off at 2pm on a Saturday and had to
be installed and running by 8pm on a Sunday. The installation was successfully carried out on time. KP Foods are now reaping the rewards in energy reduction of very low pressure drop and a constant dewpoint throughout their factory with the added reliability of the BEKO DRYPOINT RA range.
BEKO Technologies Limited Tel: 01527 575778. E-mail: email@example.com Website: www.beko-technologies.co.uk
Belzona Authorised Coating Centre - WGM Engineering Complete Large Pump Repair Application Belzona offers a solution for pump lining which has proven efficiency enhancement in the pump post application. In recent years Belzona has seen pump applications increase dramatically as companies seek to minimise running costs by tackling the issues of reduced efficiency. By way of example a power station in Northern Ireland recently sent out a tender for their Cooling Water pumps to be removed, serviced and returned to use. Prior to this, Belzona’s local engineer specified Belzona’s solutions to the power station for the repair and rebuild of their pumps and the coating of their pumps to increase efficiency. Due to their great experience and expertise in the field, Belzona Authorised Coating Centre WGM Engineering (Glasgow) won the tender. WGM Engineering removed, overhauled and installed 2 of the 48” CW circulating pumps, each weighing over 11 tonnes without the motor, that were failing to deliver sufficient flow to satisfy customer demand.
After removal, the pumps were transported to WGM Engineering’s new state of the art service centre in Glasgow and underwent a major refurbishment programme. Belzona 1111 (Super Metal) was specified for the rebuild repairs to the damaged diffuser vanes, whilst Belzona 1311 (Ceramic R- Metal) was used to repair the areas of high erosion-corrosion pitting. Belzona 1341 (Supermetalglide) was specified for the internal coating of fluid flow areas including the impellors and diffusers. This coating, which is utilised for efficiency enhancement has shown that an improvement of up to 5% can normally be achieved when coating new pumps. The main pump exteriors were coated with two coats of Belzona 5811 (Immersion Grade) to give long term immersion protection. Post refurbishment, the pumps were returned to the power station, where they were installed, aligned and commissioned by WGM
Engineers. Both pumps were returned to service within an 8 week period and within budget. The customer has expressed his great satisfaction with the service provided and is already reaping the benefits of the newly coated pumps Belzona Polymerics Limited Claro Road, Harrogate, HG1 4DS e:firstname.lastname@example.org t: 01423 567641 f: 01423 505967
Maintec Show Review
Maintenance Experts Vote This Year’s Winning Product – Hvls Fans a popular show floor feature last year
A panel of maintenance experts and an audience
when we first introduced it, and we are
of maintenance professionals have commended
entertainment again this year but also that
Pickerings Lifts for its innovative approach to
to see live demonstrations of some of
maintenance, by awarding the company with the
It’s a great way for companies to get
acclodade of winner of this year’s Lions’ Lair, a
delighted that it has not only been great it provides an opportunity for the industry the most exciting latest developments. their products noticed and in front of leading experts, as well as maintenance
Dragons’ Den-inspired contest that took place last
buyers. For the companies taking part it’s
week at the easyFairs® Maintec show on Thursday 1
by people who are really in the know. So
congratulations to Pickerings Lifts.” As well as the Lions’ Lair feature the show
The company won the competition by
thanks to its patented airfoils (blades). This
catching the eye of the panel and the
‘horizontal floor jet’ pushes air a greater
audience with its new High Volume Low
distance before it begins moving vertically
Speed (HVLS) fans, designed to provide an
and is then drawn back through the fan.
energy-efficient solution for large spaces. The new fans require much less energy
Marcus added: “We’re really pleased with
than traditional air movement HVAC based
the product, and how it works. A lot of
systems and provide year-round employee
thought has gone into putting this together
comfort and temperature.
and bringing it to market. So it’s a great achievement to receive such positive
In accepting the accolade, Marcus Clissold,
a great accolade to win, as it’s voted for
Business Development Manager of
also included a comprehensive ‘free to attend’ learnShops™ seminar programme, with speakers from Siemens, Schaeffler, and Britvic. MAINTEC, held from Tuesday 28 February to Thursday 1 March, remains a timeand-cost effective platform for suppliers to the maintenance and asset management sector, and continues to be year on year the proven place for business; the 2013 event takes place on 5-7 March 2013.
Pickerings Lifts commented: “It’s fantastic
A packed crowd of maintenance specialists
to be winners, especially as the votes were
sat and watched the action unfold as
from both the audience watching and the
Pickerings Lifts beat off stiff competition
judging panel, all of whom are experienced
from three other companies: Idhammar,
SCHAD and C-Cubed.
Making up the judging panel were Leighton
Idhammar presented its new ‘Andon
Jerry Dawson on:
Parker, Maintenance Manager at Alliance
Signalling and Business Alerts’ product.
+44 (0)20 8843 8823
Boots, Paul Dennis, Technical Facilities
Whilst SCHAD pitched ‘EXTEND7000,’ the
Manager at Experian, and Professor Len
world’s first fully functional mobile SCADA
Gelman, Chair in Vibro-Acoustic Monitoring
application, and C-Cubed showcased
at Cranfield University. All were impressed
its new EXPiDERO Inspections system.
with the fan’s capabilities.
However, they just fell short in attracting the attention of the MAINTEC Lions.
Stand bookings for MAINTEC 2013 can be made by contacting:
or emailing: Jerry.Dawson@easyFairs.com. For further information please visit: www.easyFairs.com/MAINTECUK.
The HVLS fans produce a massive, cylindrical column of air that flows down
easyFairs Managing Director UK & Ireland
to the floor and outward in all directions
Matt Benyon said: “The Lions’ Lair proved
Maintec Show Review
Maintec 2012 Proves It Remains The Maintenance Industry’s Leading Event As the doors to Hall 8 at Birmingham’s NEC closed yesterday, it remains evident that MAINTEC 2012 continues to be, after 37 years, the place where the maintenance and asset management industry comes together each year to network and keep up-to-date with the latest technological advances and techniques. The event proved a huge success yet again this year for both exhibitors and visitors, as the hall buzzed with conversations about the latest products and services on offer and visitors came away with new ideas, approaches and inspiration to improve their maintenance strategy for the coming year.
“Our goal is to be a zero loss business, that means eliminating anything such as accidents, material wastage, spillages or unnecessary downtime. The autonomous maintenance programme we’re implementing is a crucial element within that drive.
MAINTEC, held from Tuesday 28 February to Thursday 1 March, remains a timeand-cost effective platform for suppliers to the maintenance and asset management sector, and continues to be year on year the proven place for business; the 2013 event takes place on 5-7 March 2013.
“AM in our factories has already yielded major improvements in our operational efficiency on the lines it has been completed upon. An improvement of just 5% in any of our factories significantly helps us to reduce waste, energy, packaging materials and unnecessary running time, that all adds up to a huge saving, while helping to make our teams to feel more engaged in the process and give them more ownership of their machines.
Exhibitor Andy Baker, UK and Ireland Sales Manager at FLIR Systems Ltd, said: “We’ve been exhibiting at MAINTEC for a number of years now, but this year seemed one of the best yet. We launched three new thermal cameras at the show, as well as discussing our latest software and other offerings. We were delighted by the response that we got from visitors to our stand, and have picked up a number of high quality leads. Once again MAINTEC proved the perfect platform to showcase and launch our latest products.” As well as new products and services making their UK debuts, MAINTEC also played host to some new insights revealed for the first time by its expert speakers.
“We’re proving there are real commercial benefits from having highly skilled, knowledgeable operators who can care for their machines, while achieving all of this without hurting anyone in the process.” New to MAINTEC this year was ‘HAZEX’, the new specialist hazardous area, introduced to the show to reflect the growing responsibilities of engineering professionals and the growing concerns and tighter legislation over the health and safety of industrial, commercial and government sites and facilities.
safety professionals alike implement the best safety practices available and minimise the risks associated with working within hazardous areas. The area was very busy across the three days, and we had some very productive discussions with many visitors, all of whom seemed very interested and impressed with what HAZEX and MAINTEC as a whole had to offer.” The show included a comprehensive ‘free to attend’ learnShops™ seminar programme, with speakers from Siemens, Schaeffler, and Britvic. During the third day, the Dragons’ Den-inspired contest ‘Lions’ Lair’ took place, with Pickering Lifts coming out on top winning the competition with its new HVLS Fans. Matt Benyon, Managing Director of organisers easyFairs UK, concluded: “MAINTEC 2012 has to be our best yet. There was a real buzz of positivity around the show, which is an encouraging sign that British industry continues to have so much to offer. Maintenance and asset management are disciplines that are defined by efficiency, with both professionals and equipment having to work leaner, faster, and ever harder – and as such they are always focused on improvements and the latest innovations and solutions to achieve that. This is why MAINTEC continues to have a vital place in the maintenance calendar year on year, providing professionals with an effective forum to focus on product development and new ideas. We could not be more delighted with this year’s show, and hope that our exhibitors and visitors have a productive year before we welcome them back in 2013.” Stand bookings for MAINTEC 2013 can be made by contacting: Jerry Dawson on: +44 (0)20 8843 8823
For instance, Simon Hatson, Regional QSE Manager at Britvic Soft Drinks, told a packed house how the company’s autonomous maintenance (AM) initiative is already delivering major results:
Michael Dominguez, Publisher at Hazardous Engineering Solutions and supporting the new event, said: “HAZEX was the perfect opportunity for us to show how we can help engineers and health &
or emailing: Jerry.Dawson@easyFairs.com. For further information please visit: www.easyFairs.com/MAINTECUK.
St. Richard’s Hospital Laundry On Course To Save Over £14,000 A Year In Energy Costs Following Fitting Of Gem Steam Traps St Richard’s Hospital, part of Western Sussex Hospitals NHS Trust, is making significant energy savings in its laundry department following the installation of Thermal Energy International’s GEM venturi orifice steam traps.
“Over a ten year period the hospital has the potential to save £155,000 on gas alone based on present costs”, said Richard Harris. “In addition, as the GEM traps do not fail, we will save money on downtime and replacement costs. A further added bonus is that the traps only have to be cleaned once a year.” The GEM traps are also helping the hospital reduce its carbon emissions in line with the Trust’s Carbon Management Plan, which commits the Trust to reducing its CO2 emissions by 16% between 2010 and 2013 and to making energy savings of £844,000 over the same three-year period. Under the Government’s CRC Carbon Reduction Scheme, large energy users, such as hospitals, will this year start to buy allowances for each tonne of carbon dioxide at a rate of £12 per tonne per annum. As a consequence, participants successful in reducing energy consumption will not only save money on energy bills, but will also need to purchase fewer allowances. Instead of utilising a valve mechanism to close off steam, the highly efficient GEM steam traps use the venturi orifice design to effectively drain condensate from the steam system. As the GEM steam traps have no moving parts to wedge open or fail, they provide the ultimate in reliability, necessitating only minimal maintenance and requiring no spares, testing or monitoring equipment.
The GEM traps are expected to save the hospital over £14,000 per annum in energy savings alone, as well as additional reductions in replacement traps and maintenance costs. St Richard’s Hospital has 430 beds and provides a full range of general acute services including maternity, outpatients, A&E and intensive care. The recently redeveloped laundry complex services the whole hospital handling a throughput of around 70,000 pieces per week. Steam is used as a primary source of energy throughout the laundry in the operation of a wide range of equipment including washers, ironers, collators and dryers. Conscious that the laundry’s mechanical steam traps were causing water vapour losses through evaporation from the hot well as well as poor condensate return, Richard Harris, Head of Engineering and Estates Standards, decided to investigate the GEM venturi designed steam
traps. “We considered chemical treatment, but decided to also explore the GEM traps as we were also finding that a significant proportion of the laundry’s steam traps were failing. As the GEM traps come with a 10 year guarantee we thought this might prove the solution”, said Richard Harris. Thermal Energy International carried out a survey of the laundry’s steam traps using an infrared thermometer. This found that over 26% of the mechanical traps had failed partially open which was causing problems within the system. From these findings, Thermal Energy International was able to calculate that by replacing the mechanical traps with the GEM venturi design, St Richard’s Hospital would be able to save over £14,000 in energy and maintenance per annum alone, providing a short-term payback of less than 2 years.
Available in a wide range of sizes for a full cross section of applications, the hardwearing GEM steam traps are manufactured from corrosion resistant stainless steel and are guaranteed for 10 years, obviating the need for repair or replacement. The GEM steam traps provide a fast payback - on some processes within a matter of days - from reduced energy costs and increased equipment reliability due to a reduction in damaging steam within the condensate system. In addition they improve product processing by enhancing the quality of steam which in turn reduces equipment repairs, downtime and replacement costs.
For more information, visit: www.thermalenergy.com & www.gemtrap.com.
Online Condition Monitoring
On-Line Monitoring Of Power Plants Using Hybrid Equipment Models Dr. Elmer Hansen, Principal Engineer GENERAL PHYSICS CORPORATION
incipient problems is now an essential tool in the hands of asset managers. It alerts managers to sensors in equipment that have moved outside of the normal operating ranges so that they can make good timely decisions as shown in Figure 1.
Sam Rohmer III, Control Room Operator CPS Energy ABSTRACT As power generating companies seek to improve plant reliability, maintain efficiency, and increase outage intervals, many are turning to on-line performance and condition monitoring to augment traditional high-low control system alarms. Such monitoring systems employ advanced modeling techniques for automated early detection of incipient problems and are an essential element in an effective asset management program. Early warning provides a reduction in repair costs, an increase in equipment run times, reduction in fuel costs, reduction in replacement power cost and economical use of planned or unplanned outages. Traditional first principles models provide the ability to detect of abnormal behavior based on engineering relationships related to heat transfer, conservation of mass and energy, and fluid dynamics. Empirical models use historical data to accomplish the same goal on equipment where a first principles model is unavailable or overly complex, (turbine shaft, fan bearings, damper settings, etc.). This paper describes a new method which uses hybrid equipment models based on both empirical and first principles techniques. Such hybrid models incorporate elements unique to each method to provide comprehensive monitoring of all plant equipment. The on-line monitoring system to be discussed uses hybrid physicalempirical models to detect abnormalities and alert plant personnel. Asset managers use the refined detection information from models to oversee the six major plant concerns of reliability, efficiency, environmental, chemistry, fouling, and cycle leakage. Numerous case studies demonstrating the results of the hybrid models at a coal-fired power plant are included.
Figure 1 Management tool to turn Data into Decisions Companies have successfully used first principle-based performance monitoring systems to track parameters such as boiler efficiency, turbine cycle heat rate, condenser pressure (shown in Figure 2) and steam turbine efficiency, as well as overall plant heat rate. General Physics’ EtaPRO™ and VirtualPlant™ technologies utilize first principle engineering relationships such as heat transfer, thermodynamics, and fluid dynamics to quantify degradation and need for overhaul. These same companies have also successfully used empirically based condition monitoring systems such as EtaPRO APR™ to detect anomalies associated with rotating equipment bearing behavior, Figure 3.
INTRODUCTION As power generating companies seek to improve plant reliability, maintain efficiency and increase outage intervals, they are turning to on-line monitoring to assist in this task. On-line monitoring has greatly enhanced the traditional high-low control system alarms. Automatic early detection of
Online Condition Monitoring
Figure 2 First Principle calculation of condenser pressure managers for timely decisions, Figure 5.
Figure 5 APR Process - Data, Model, Concerns, Reporting
Equipment behavior is shown to be abnormal when the actual measured value moves away from the historical (or expected) value of the model. In Figure 6, the IB (inboard) motor bearing temperatures are well correlated with the motor stator temperature. However, the OB (outboard) bearing temperature has some points that are outside of the normal range of operation. These are abnormal.
Figure 3 Empirical calculation of vibration
Figure 6 Normal and abnormal reference data
The behavior of bearings, shafts, damper positions, etc. is currently beyond the reach of first principle models. VirtualPlantâ„˘ and EtaPRO APRâ„˘ are two very different modeling methods that have one thing in common: they both provide the user with an expected value that can be compared with the actual value. EtaPRO APR (Advanced Pattern Recognition) uses normal historical data as the basis of the empirical model. Localized modeling is used to provide the expected values of model points. The APR algorithm selects historical time slices that are near the current time slice and uses a weighted average of these to predict the expected values. Figure 4 is a comparison of these two modeling technologies:
The automatic early detection of both performance and integrity issues gives the operator or analyst the ability to concentrate on solving problems rather than searching for a potential problem. Performance and integrity calculations are brought together in hybrid asset models. These models allow the user great flexibility in that actual values can come from sensor measurements or calculations and real-time expected values can come from an APR model, a Virtual Plant model, or an EtaPRO Point ID.
For example actual and expected values pairs might be:
Figure 4 Hybrid Modeling using first principle and empirical modeling The goal of the hybrid models is to monitor the six major areas of plant concerns: reliability, environmental, chemistry, efficiency, fouling, and cycle leakage, (field examples in each of these categories are discussed further on in this paper). Data for the plant assets are compared to the various asset models and abnormalities are brought to the attention of asset
PRESENTING RESULTS Having the right combination of modeling techniques to accurately predict expected behavior forms the foundation of effective monitoring for anomalies. Equally important is the ability to display, organize, and manage such anomalies as they occur. The EtaPRO Concerns Viewer shown in Figure 7 is one such implementation. Each row represents a measured or
Online Condition Monitoring calculated point along with its corresponding model attributes (expected value, normal operating range, and deviation). The red and blue bars show the time and direction of the anomaly, (red is high and blue is low). Pre-defined trends are available for every modeled parameter and can be displayed beneath any selected point row.
ENVIRONMENTAL Boiler Air Damper Maintenance. Correct boiler combustion is essential to maintaining proper emission levels. Correctly functioning boiler dampers deliver the desired amount of air and fuel to maintain correct boiler combustion. Boiler dampers can fail by sticking in one position and by
Figure 7 Concerns Viewer
When enlarged, the trend displays a yellow line as the actual value along with a light blue line representing the predicted value on a gray zone of the normal range of operation and a purple line showing the deviation plotted at the bottom. A concern is triggered when the actual value is outside the gray zone for a user-specified period of time, with the concern marked with a red cross, Figure 8.
Above: Figure 10 dragging behind the command signal. The Boiler damper model uses the damper position as the actual value and the damper demand as the expected value (an EtaPRO point). When the two values are different for a sufficient time, a concern is triggered. As seen in Figure 11, the first damper is stuck in one position as the demand tries to move it. The second damper shows a damper that drags behind the demand. It responds but not all the way.
Figure 8 Region of normal operation and indication of abnormality The early warning presented through the EtaPRO Concerns Viewer can help produce a reduction in repair costs, a life extension of equipment, a reduction in fuel costs, a reduction in replacement power cost and a reduction in EFOR through the use of planned or unplanned outages. Concerns typically fall into these six major areas: reliability, environmental, chemistry, efficiency, fouling, and cycle leakage. These are not exclusive categories but have overlap and interaction. The following sections provide specific examples of applying hybrid models to a working coal-fired generating plant. RELIABILITY Ash Pump Thrust Bearing. Reliability is important to rotating equipment. The first example, Figure 9, shows the heating of an ash pump thrust bearing. The source of the problem was found to be a lack of cooling water. The auxiliary cooling water was shut down to replace a line to the PA fans but the cooling water was not correctly swapped on this pump. Had the screen below been available to operations, as it now is, the pump situation would have been corrected without turning the pump off.
Figure 11 Abnormal boiler damper operation Four months of keeping up with damper repairs have almost all the dampers operating properly. The blue and red bars indicate the times when the damper was in concern. The time period of the bar chart is 2/1/2011 to 5/6/2011. By looking at the bars one can see the progress that has been made, Figure 12.
Figure 12 Increase in correct boiler damper operation
CHEMISTRY Boiler chemistry can also be monitored (Figure 13) to obtain two benefits. First, bad readings from instruments can be quickly detected and repairs made. Second, on-line instruments give quicker indication of abnormal chemistry than do daily samples. This allows operations to take immediate corrective action to mitigate damage. Figure 9 Abnormal bearing temperature Service Air Compressor. This air compressor has been shutdown to replace a motor bearing which staff believe is causing the high bull gear vibration seen in Figure 10. Since there are three air compressors, this one can be taken out of service and repaired at the plantâ€™s convenience. Having early warning of the change in vibration, allows the compressor to be repaired before the problem becomes more costly.
Page Header Online Condition Monitoring Bottom right page 32: Figure 13 Boiler Chemistry EFFICIENCY High Energy Drain to Condenser. The condenser pressure as seen in Figure 14 suddenly increased. The problem was found to be that the cold reheat drain to condenser opened up because of a bad level switch. The level switch is isolated and will be fixed on the upcoming outage. If the plant had temperature sensors on the drain lines before the drain valve that would have provided an additional indication of the source of the problem. Lacking such instrumentation the condenser must be walked down to find the source of the problem. Figure 17 Cost of high condenser pressure with the accumulated cost between March 8-12 of $67,000. This is exacerbated by low hot reheat temps. Reheat Temperature Control Problem at Low Loads. A third efficiency related item deals with low hot reheat temperature and hot reheat spray seen in Figure 18. Each item itself causes a heat rate penalty. They should not occur together but in this case they do. The model uses an EtaPRO calculation to provide the expected values of spray and hot reheat temperature. At very low loads hot reheat temperature becomes difficult to maintain. During the same time, reheat sprays are active and which should not be needed. This only increases the loss. Figure 14 High condenser pressure
Figure 15 Confirming hotwell temperatures This condenser pressure rise was also confirmed using hotwell related temperature sensors, Figure 15.
Figure 18 Excessive reheat spray Based on the cost of being off target shown in Figure 18, the loss due to low hot reheat and reheat sprays is $886 per day (Figure 19).
Condenser Air In-leakage. The second condenser example (Figure 16) looks very similar to the first but had a different root cause. Some drains were leaking into the condenser and a rupture diaphragm and other minor areas were leaking air into the condenser. They have been temporarily fixed and will be repaired during outage. The condenser diagnostics module pointed to the air inflow problem.
Figure 19 Cost of RH sprays and low RH temperature
Figure 16 High condenser pressure The cost of the high condenser pressure in the first example was calculated using the integral over time of the data shown in Figure 17 (top right)
High Pressure Feedwater Heater Tube Leak. The fourth example looks at a leak in a high pressure final feedwater heater. The leak started on 1/16/2011. A jump is seen in heater 7 valve demand and heater 6 valve demands (Figure 20). When the valve demand is converted to a flow, the jump in demand represents a flow of about 30 KLB/HR. This corresponds well to the sonic flow at saturation conditions for one open tube. There is a second jump on 1/18/2011 of the same magnitude indicating a second tube has opened. The additional flow drove the heater 6 drain valve fully open and began to open the emergency drain valve. There are
Online Condition Monitoring
Figure 23 Recirculation valve in manual Figure 20 Feed water heater tube leak
FOULING One area of fouling that requires constant attention is motor filters. These filters get dirty regularly in a coal-fired power plant and are very dependent upon local condition such as field and construction dust for outside motors and coal dust for inside motors. Figure 24 shows the development of a dirty filter. On the afternoon of the 4th, a concern is triggered in the heat of the afternoon. On the afternoon of the 6th, the temperature is much higher. The expected values drop down; because the model is set to remove sensors from actively contributing to the model once the measured values are too far from the expected. The value of catching a filter change early is that it keeps the motor cooler and gives extra time to change the filter before reaching an alarm or shut down point. In this case, motor filter changeout is based on actual condition, not time or personal preceptions.
Figure 21 Cost of heater 7 (top heater) out of service corresponding increases in heater levels for both heaters. Finding a leak early and isolating the heater can reduce the collateral damage and extend the life of the heater. This heater has been in service 34 years and has 27 of 1010 tubes plugged. The heater isolation valves are leaking so that the heater cannot be totally isolated. The heater will remain out of service until a several day offline outage is available to plug the tubes. The cost of being out of service is about $130 per hour or $3120 per day as seen in Figure 21. Condensate Pump Recirculation Valve. The next two events deal with the recirculation valves of pumps. Figure 22 shows strip charts for a condensate pump which had the recirculation valve left in manual. The valve was closed and the system returned to normal. In his case there was no point to indicate the percent open of recirculation valve.
Figure 24 Development of a dirty motor air filter
The air heater X-ratio calculated in an EtaPRO point (Figure 25) is used to look at boiler and boiler ducting air in leakage. At this time there has not been a change in the X-ratio. Cycle make-up flow is also calculated by an EtaPRO derivative of the make-up tank level. It will be used in the detection of a boiler tube leak.
Figure 22 Recirculation valve left in manual Boiler Feed Pump Recirculation Valve. The boiler feed pump recirculation valve of the same unit had to be controlled manually because of a failure in maintaining the desiccant in an instrument air dryer at a regular interval; which contaminated the air system with (now) powered desiccant. Figure 23 shows that the recirculation valve was open when it should have been closed. This valve had to be controlled locally in the field during load drops. In this case it was not closed after the load had increased which went unnoticed by the operators until the speed controls on the feed pump maxed out bringing an alarm to the DCS. This valve will be changed out during upcoming outage as well as purging the remaining desiccant out of the instrument air system.
Figure 25 X-Ratio monitoring to detect excess air in leakage
SENSOR PROBLEMS The type of problem encountered most frequently is a sensor that gives a reading within the normal range of operation but is not correct. When a sensor fails to read correctly it may fail near an ambient temperature, it may read high or low, or it may be erratic. The DCS and the historian often indicate that the signal is good even though it is not. Hybrid models have the ability to predict expected sensor values taking into account design
Online Condition Monitoring
Figure 26 Temperature abnormality performance (VirtualPlant) and past performance (EtaPRO APR). These models consider changes in ambient conditions, load, and equipment in service to better estimate a sensorâ€™s true value. This information aids in instrument maintenance. Regulator Control Problem. A hybrid model will often confirm a sensorâ€™s reliability even when it appears to be faulty. Figure 26 shows an example of an erratic sensor initially thought to be in error. The erratic behavior, first thought to be a sensor issue, turned out to be a regulator having difficulty controlling the leak-off temp on the outboard bearing of the boiler feed pump drive turbine. A bypass valve opened up around the regulator making the issue harder to identify.
The hybrid models available in EtaPRO bring together two tool sets that have up to this point existed separately. The combination of first principle and empirical models has been able to provide the ability to monitor the entire range of power plant equipment from thermal performance, operations and maintenance perspectives. Presenting the results of the hybrid models in a real-time environment with appropriate display and concern management tools, allows the operator or analyst the ability to monitor performance and condition from the same screen. It provides a way to quickly identify abnormal equipment behavior and direct resources to resolve the problem in addition to determining the resultant financial impact. The system described has proven highly effective at detecting abnormal plant and equipment behavior and for targeting limited manpower resources to specific problem areas.
Online Condition Monitoring
Brüel & Kjær Vibro has delivered plant-wide condition monitoring systems to the O&G and petrochemical industry for over 20 years The oil & gas and petrochemical industries face the most demanding challenges in fulfilling today’s machine management and reliability requirements.
An integrated plant-wide machine condition and performance monitoring strategy is essential to achieving this. Since its inception in 1991, Brüel & Kjær Vibro’s Compass platform has been the industry leading integrated monitoring solution. Successfully utilized in refineries, offshore and onshore oil & gas production facilities, LNG, olefin, polyolefin and chemical plants, the system has delivered considerable uptime, efficiency and cost benefits to customers the world over. Combined with our global sales and technical support network, Compass can deliver uptime to your plant! Brüel & Kjær Vibro is part of Spectris plc, the leading supplier of productivity enhancing instrumentation and controls. Contact: Brüel & Kjær Vibro, e-mail: email@example.com, www.bkvibro.com
Online Condition Monitoring
Brüel & Kjær Vibro provides a comprehensive integrated monitoring solution to the hydro industry Hydroelectric power plays an increasingly important role in the worldwide energy market. As the Operation & Maintenance
these machines becomes imperative. Over
requirements become more demanding,
the past 20 years, Brüel & Kjær Vibro has
the importance of effectively monitoring
built a global customer base by monitoring
all types of turbines ranging from 1MW to 1GW. Our dedicated hydro monitoring systems are tailored to the varying demands of the hydro industry and include unique specialized functions including the multiple machine state monitoring function - ideal for pumped storage applications. In addition to comprehensive vibration monitoring, Brüel & Kjær Vibro also provides integrated air gap, magnetic flux, process, performance and cavitation monitoring. Combined with our global sales and technical support network, we can provide a solution to your Hydro application! Brüel & Kjær Vibro is part of Spectris plc, the leading supplier of productivity enhancing instrumentation and controls. Contact: Brüel & Kjær Vibro, e-mail: firstname.lastname@example.org, www.bkvibro.com
Make Sure Your Machinery Is Running In Top Form; Follow These Tips From SKF For Proper Alignment And Maintenance An important part of keeping equipment running smoothly involves regular monitoring and maintenance to ensure the machinery is properly aligned.
Misaligned shafts and belts on rotating equipment can increase the risk of costly, unplanned downtime. Misalignment can also damage seals and couplings and lead to subsequent lubrication problems. In these situations, correcting shaft or belt misalignment is the only way to forestall future seal failure and associated loss of lubricant. When shafts or belts are improperly aligned, it increases the load on them, potentially resulting in a range of problems that can have a direct impact on a company’s bottom line: • Increased friction, which can lead to excessive wear, excessive energy consumption, and the likelihood of equipment breaking down prematurely •
Excessive wear on bearings and seals, resulting in premature failure
Premature shaft and coupling failure
Excessive seal lubricant leakage
Failure of coupling and foundation bolts
Increased vibration and noise
To help prevent these potential problems, SKF offers the following tips and suggestions: •
There are basically two kinds of shaft misalignment: parallel (or offset) misalignment and angular misalignment. With parallel misalignment, the center lines of both shafts are parallel to one another, but they are offset. In angular misalignment, the shafts are at an angle to one other. You need to consider both possibilities when checking for misalignment. Don’t rely solely on visual inspection to check alignment. Dial indicators are somewhat more accurate, but don’t provide real-time values to help technicians to simultaneously measure and attain correct alignment. Instead, dial indicators must be removed and reinstalled after each
alignment adjustment is completed. Neither method provides the level of accuracy required by much of today’s precision machinery. •
Today’s laser-guided tools are quick, easyto-use and accurate. They typically consist of two units that emit and detect a laser beam, and a handheld control device. The handheld device displays real-time coupling and foot values (which indicate moveable machine foot positions to facilitate corrections) during the alignment process, eliminating the need to remove and reinstall the measuring units after each adjustment. In addition, the laser system tool documents the values, which can be downloaded to a computer and used to benchmark future alignment inspections.
When inspecting for misalignment, be sure to account for “soft foot,” a condition where one foot of a machine does not sit flat on the base plate. Shim plates generally can be used to bring machines back into alignment.
Institute an ongoing alignment maintenance program to document alignment conditions before a machine is removed from service and to make sure any misalignment is properly detected, analyzed and corrected.
SKF offers a complete line of laser-guided shaft alignment systems. The TKSA 60 and TKSA 80 Shaft Alignment systems are designed for both novices and experienced users. Each provides a complete built-in alignment process that takes users from preparation and evaluation all the way through to correction and documenting the results achieved. Each system’s built-in wireless module eliminates the need for additional cables and devices, creating a faster, more efficient tool to collect the necessary alignment data. Complementing TKSA 60 and TKSA 80 Shaft Alignment systems are the laser-guided TKSA 20 and TKSA 40 utilities. The TKSA 20 is an easy to use shaft alignment tool designed for both beginners and experts, while the TKSA 40 offers a graphical interface and additional features, such as the ability to check alignment using pre-installed or userdefinable tolerance tables built into the system.
SKF is a leading global supplier of bearings, seals, mechatronics, lubrication systems, and services which include technical support, maintenance and reliability services, engineering consulting and training. SKF is represented in more than 130 countries and has around 15,000 distributor locations worldwide. Annual sales in 2011 were SEK 66,216 million and the number of employees was 46,039. www.skf.com
Remote Visual Inspection Technologies – its all about light
This article is one of a series designed to introduce the reader to various inspection technologies available, and look at some of the requirements that lead to choosing the right equipment for the right inspection task. Camera technology continues to leap forward on an almost daily basis, and you only need to visit your local retail park to see that the capability of digital imaging is now far beyond what we could only dream about a few years ago. These advances are mirrored in industrial imaging market, particularly with the advance of the capabilities of the CMOS chip technology, helping to reduce the cost of simple systems. While CCD chip technology still retains a quality edge, particularly in the video endoscope arena, there are many instances when for the larger camera head systems, a CMOS system gives good enough results.
inversely proportional to the square of the distance, so the light levels at 1m from a source will be a quarter of those at 0.5m. It is important to realise that this needs to be considered in conjunction with the light sensitivity of the imaging system. When insufficient light is available most camera systems will deliver either a very
dark image, or the image displayed will become very grainy or pixelated. The latter is normally caused when the automatic gain control (AGC) reaches its limit – more expensive systems can allow the user to increase image integration times to maximise available light, but this will require the camera to remain steady during the process. It is better wherever possible to use a camera suited to the task, however we frequently face a challenge where the access is the limiting factor, for example if you are looking to inspect a 2m dia. vessel, but access is through a 50mm dia. pipe then the use of an INVIZ PIPE camera with very low light sensitivity and strong illumination and autofocus will ensure a good inspection.
“A remote visual inspection system is completely dependent on the light available” As with all visual camera systems, having sufficient light is the most important requirement, and here again, it is the advent of LED’s that have revolutionised the ability of a system to deliver light to the subject that has helped reduce the cost and size of camera systems. It is important to note that light levels fall off at a rate that is
About the Author: Paul Sacker is Managing Director of Crimson Industrial Vision Ltd, a company specialising in the supply of Remote Visual Inspection and Thermal Imaging systems for the industrial market. He can be contacted at email@example.com or visit the website at www.crimsoniv.co.uk
Impact of manufacturing methods on tube failure due to flow induced vibration Since its inspection, shell and tube heat exchangers have proven to be the most robust heat transfer equipment. Since the industrial revolution, heat exchangers have been a necessity in terms of harnessing and distributing energy. In 1923 the world saw the introduction of the first commercially-available plate heat exchanger by Dr Richard Seligman, founder of APV, though the original idea was patented in the latter part of the 1800’s. Plate heat exchangers rose to popularity, due to its cost-effective nature – particularly in the 1970’s in the face of the energy crisis. Developed during an era of industrial progress, plate heat exchangers could be mass produced on the production line courtesy of Henry Ford. Unlike the plate heat exchanger, the shell and tube exchanger has to be custom designed and built for each application. This makes the shell and tube exchanger costly to produce and as such has lost market to the cheaper, plate exchanger alternative. However, the shell and tube remains the most robust and maintainable of the heat exchangers and retains the monopoly in the refinery industries as they provide a highfidelity solution to a high-risk and pressure application. Thanks to a possibility of double tube sheet designs, which removes the possibility of fluids mixing, the shell and tube exchanger has retained application in the hygienic and pharmaceutical industries. Though not common, shell and tube heat exchangers are sensitive to flow-induced vibrations and if not properly accounted for can cause tube failures in the heat exchanger. According to TEMA (Tubular Exchanger Manufacturers Association) standards as laid out in their latest edition; “The fluid flowing inter relate with heat exchanger geometry and can cause heat exchanger tubes to vibrate. This phenomenon is highly complex and the state of the art is such that the solution to this problem is difficult to define. Due to the complexity of the problem, the TEMA guarantee does not cover vibration damage.”
There are three main types of vibration mechanisms; Vibration Fluid-elastic Instability, Acoustic Vibration, and Vortex Shedding which affects the frequency mode damages caused. As detailed by TEMA (8th Edition, page 95, V-2), mechanical failure of tubes resulting from flow-induced vibration may occur in various forms and damage may result from any of the following independent conditions, or a combination of the following: Collision damage from the impact of tubes against each other or the vessel wall, due to large amplitudes of the vibrating tube. The tube wall eventually wears thin, causing failure. Baffle tube holes are also susceptible. Baffle tube holes requires a manufacturing clearance over the tube outer diameter to facilitate fabrication. When large fluid forces are present, the tube can impact the baffle hole causing thinning of the tube wall in an uneven manner. Tube sheet clamping effect; tubes may be expanded into the tube sheet to minimise the crevice between the other tube wall and tube sheet hole. The natural frequency of the tube span adjacent to the tube sheet is increased by the clamping effect. Flaws contained with the material and strategically oriented with respect to the stress field can readily propagate and actuate tube failure. Acoustic vibration and resonance is due to the gas column oscillation and is excited by phased vortex shedding. The oscillation creates an acoustic vibration of a standing wave. The generated sound wave will not affect the tube bundle unless the acoustic resonant frequency approaches the tube natural frequency. When the acoustic resonant frequency approaches the tube natural frequency, any tendency towards tube vibration will accentuated with possible
A Shell and tube heat exchanger under construction. tube failure. As cited by Exxon Mobile at the NPRA Maintenance and Reliability conference (2011), tube damage from flow-induced vibrations has increased over the years. “This is primarily as a result of advances in catalyst and control technologies which allow operators to increase plant capacity by simply increasing the flow through existing process equipment. In addition, new exchanger designs are smaller which entails greater shell-side velocities.” Predicting tube failure is a crucial step in the design process, but accurately forecasting vibration is the most challenging of all. Current predictions of vibration failure are still complex with many factors contributing. The best commercial software still uses simplistic approximations and do not consider all the variables. This is despite newer generation technological advancements. Engineers today have at their disposal Computational Fluid Dynamics (CFD) which enables accurate fluid-flow phenomena prediction, combined with Finite Element Analysis (FEA), which accurately predicts stressors in complex geometries such as tube bundles. Yet failures as a result of vibration are on the increase. TEMA details that the current state of the art flow-induced vibration correlations are not sophisticated enough to warrant treating the multi-span tube vibration problem (or mode shape other than the fundamentals) in one comprehensive analysis. Therefore, the potential for
Figure 1: Tube in compression 9.75Hz.
Figure 2: Tube no load, 27.02 Hz.
vibration is evaluated for each individual span, with velocity and natural frequency conserved being that of the unsupported span under examination. According to JM Chonoweht, Flowinduced Vibration, Heat Exchanger Design Handbook, (1983), when comparing post-tube failure predictions of actual data from the HTFS Data Book, correct predictions were made for 48 of the 67 cases – or 72% correct. Of the cases with no vibration reported only about 50% were predicted correctly. This substantiates the claim of Ignatius Herbst*, M.Eng (chemical), managing director of Logichem Process Engineering and Projects in South Africa, that the model of calculations is only as strong as the input data provided by the engineer. “It is interesting to note from the above quote, that only once the tubes were investigated thoroughly post failure, were better predictions made,” says Herbst. One contributing factor to inaccurate tube failure predications is the incorrect application of compressive axial load on tubes. According to TEMA (8th Edition, pg 122, V 13-9), “The heat exchanger designer must recognise the potential adverse impact on vibration by compressive axial loading of tubes due to pressure and/or temperature conditions. This is particularly significant for tubes in single pass, fixed tube sheet exchangers where the hot fluid is in the tube side, and in all multiple-tube pass fixed heat exchangers. The use of an expansion joint in such cases may result in reduction of the tube compressive stress.”
Figure 3: Tube in tension, 36.70 Hz.
The subject of this editorial is based on a real case faced by Herbst, where compressive axial stress, induced in the tubes as a result of the tube to tube sheet joint, led to incorrect Vibration Analysis and ultimately to limited tube failure. “TEMA lists three possible tube-to-tube sheet joints methods; Welded; Expanded with and without grooves; Seal welded and expanded. Unfortunately, TEMA does not dictate a mandatory method to follow to avoid or limit the introduction of compressive stress in tubes due to tube-totube sheet joint. Therefore, end-users and their engineering partners will often dictate to manufactures how the tubes should be fixed to the tube sheet,” remarks Herbst. “In this case, the end user specified, strength
welded and expansion of tubes. Coupled to this, the end user also specified a sequence i.e. weld and then hydraulically expand the tubes. This sequence led to very high compressive stresses in the tubes.” Why do expanded tube-to-tube sheet joints induce compressive load on the tube? The laymen explanation presented by Herbst: “When expanding the tube into the tube sheet, the tube expands similar to tubular balloons used by balloon artists. The tube will expand in all directions however the expansion in the length down the axis is more than the increase in diameter. This axial expansion is not a problem during the first joint as the tube is free to expand, however fixing the second joint at the other end followed by its expansion results in axial compressive stress. In the case were the tubes are first welded, both expansions lead to an increased compressive stress.” “The magnitude of the compressive stress is dependant on the unsupported tube span or Baffle spacing. If long tube spans are used the tubes would bow more profound and the axial compressive stress would lessen. Shorter tube spans result in less bowing but higher stress.” “HTFS and HTRI, the leading shell and tube design software, includes compressive stress due to operating temperatures and pressure comprehensively, but do not allow for, or calculate the compressive stress induced during the manufacturing process. It is up to the designer to specify any pre-stress conditions. By omitting this compression stress, flow-induced vibration calculations are null and void.” The cautionary statement Herbst wishes to communicate is that the actual assembly process should be considered when predicting flow-induced vibration. * Ignatius Herbst is the managing director of South African based companies, Logichem Process Engineering and Logichem Process Projects. The companies service the engineering needs of the pharmaceutical, refinery, distillation and food and beverage industries in Africa, with scope to expand into overseas markets.
For more information, visit: www.logichemprocess.com
Logichem Process Engineering Logichem Process Engineering (LPE) offers a wide range of Heat Exchangers – manufactured and supplied in various materials and designed with the most advanced process, thermal and mechanical software. All of LPE’s Heat Exchangers comply with the TEMA and ASME codes. LPE’s Heat Exchanger range includes: • • • • • •
Hygienic, Double Tube-Sheet Exchanger for the Pharmaceutical Industry. Shell and Tube to all TEMA Classes and Types. Electric heaters certified for use in Explosive Atmospheres, Ex d IIA T3, other gas groups and temperature class are available. Condensers. Re-boilers and Evaporators. Atmospheric Vaporisers (Longitudinal Fins).
For more information, contact: Mr Ignatius Herbst (Managing Director) Email: firstname.lastname@example.org Or visit us at:www.logichemprocess.com
An Explosive Proof Syngas Ex d Heater.
Robotic - In-Situ and Fast Clean of Heat Transfer Plant no record of any improvement was made after the original cleaning. When exchangers are finally opened up to ascertain the extent of fouling it is not surprising to find it is so severe that cleaning takes a lot longer than planned Shell and tube Heat Exchangers are the real challenge is that by then exchangers and becomes critical path. Any benefit unsung heroes of most heavy industrial are so fouled a traditional cleaning that might have been gained by a quick sectors and are often taken for granted. approach is often inadequate. traditional clean is offset by the extended Nobody likes paying for what is often seen What aggravates the situation is that heat cleaning duration and costs plus lost to be unnecessary maintenance. Heat exchangers are rarely cleaned properly in production due to the remaining fouling. exchangers provide duty for so long and the first instance and the commercial need The most common type of heat exchanger their drop in efficiency, usually a gradual to keep it on-line merely exacerbates fouling is the shell and tube exchanger, whether process, goes largely unnoticed (as does build up, making it even harder to clean and straight or hairpin floating head. With the fuel and production losses) until inspect. When the decision is made to carry hundreds or thousands of small-bore tubes, performance has deteriorated sufficiently out cleaning very few operators know what quite modest scaling requires major work to to be a problem. Then it really is a problem the performance of the exchanger is meant return the exchanger to “as commissioned” that requires urgent attention. However the to be, either because drawings are lost or performance. If the shell (outside) of the bundle is heavily scaled too, the cleaning challenge rises by an order of magnitude. No matter how snazzy your multi lance bundle cleaner with bundle rollers, you will never achieve 100% surface scale removal, inside and especially outside tube surfaces. Accessibility = Cleanability = Inspectability. Heavy industrial plants are never built with a view to accessibility therefore it follows that they are not designed for cleaning and inspection. The heavy industrial sector is still “making do” by installing 80+ year old exchanger technology and still cleaning it with 80+ year old cleaning technology i.e. water, chemicals and maybe a mechanical system here and there. Of course focus on productivity is essential but surely the ability to keep things performing after the first year must be of equal importance. There is massive potential to bring about significant improvements in heat exchanger design i.e. accessibility and ‘clean-ability’ by working more closely with the people who know about all the cleaning methods that exist and who will then design and fabricate industrial plants around those systems. Better design leads to improved access, better, faster, safer cleaning, even cleaning in-situ and on-line with less waste issues. Easier and quicker cleaning of exchangers, back to as new duty is a walk in the park with spectacular savings. Plants are specified and ordered on the basis of throughput. Suppliers are happy to comply with this and design heat CCR Platformer shell side before Tube Tech clean exchangers with 30-40% excess capacity
By Mike Watson, Technical and Managing Director of Tube Tech International Ltd
Heat Exchangers to “allow” for fouling. A classic case of the “because it’s been done this way for so long, why change,” scenario. When it comes to maintenance, refineries - like most of industry - tend to compete on the same basis - a 21-day shutdown is decreed because it’s been done that way for maybe the last 20 years. The same cleaning methods are generally used slavishly, with high-pressure water as the cleaning medium. Most companies look at their heat exchangers in isolation and simply try to extend their run-time, instead of having them designed or re-designed so they can be cleaned more regularly and more easily. A leading UK refinery, for instance, managed to reduce cleaning time on one crude shell-and-tube exchanger from three days to three hours by applying a nonconventional approach to cleaning. If a plant could be optimized for cleaning, full production and heat transfer coefficiency could be maintained throughout its run time between shutdowns. Relatively minor mechanical changes means each exchanger can be accessed and cleaned while others remain on-line. A redesign of each exchanger means it can then be cleaned with a different system to standard high-pressure water jetting or chemicals in a few hours instead of several days. As an example, Saudi Aramco, ExxonMobil and Shell refineries around the world needed to clean their fouled CCR Platformer Texas Towers (also known as Vertical Combined Feed Exchangers – VCFE). These exchangers are approximately 25m tall and contained several thousand scaled and blocked tubes as well as shell side fouling. Historical cleaning duration had taken between 12 and 50 shifts. A new approach took 3 to 7 shifts. A multi feed drill lance system was used to unblock and de-scale all the carbon steel tubes at 2 minutes per tube. The shell side was cleaned by lifting the bundles out but instead of lying them on the ground, the exchangers were lowered and supported inside a bespoke frame for cleaning to be carried out whilst still in vertical mode with no risk of distortion to the tube bundle. Shell side cleaning was completed using a patented PlatejeTT™ process, using a
CCR Platformer shell side after Tube Tech PlateJeTT clean combination of ultrasound, mechanical shear and polymeric water pressures of between 1000 and 4000 bar. The most severe hydrocarbon coke was removed with ease and quickly back to as new performance. Heat exchange surfaces remain smoother for longer providing better heat transfer co-efficiency. If and when the exchanger does foul up, it’s easier to clean next time
In the words of Red Adair “…if you think employing a professional is expensive, try employing an amateur.” around. This would represent a change of practice to what has been the norm since the 1940s.It was at this time that Mobil in the UK was one of the first refineries who decided to extend run-times by abandoning the annual clean and only clean every two years. Today, typical service intervals have become stretched to four years or more but the apparent operational savings are often a false economy. Heavy industry operators think they have little choice but to play the same game or lose millions during frequent shutdowns. Four years down the line, however, the plant will have to come down for major cleaning and maintenance and it will likely experience a far higher capital replacement cost than ever before.
So providing your heat exchangers do not foul and providing you have the “very best practice” in cleaning and inspection clean more regularly and consider modifying or building your plant with a view to accessibility for cleaning!
Contact: Tube Tech International Tel: +44(0)1268 786999 Email: email@example.com Web: www.tubetech.com
Smaller-Diameter Round Copper Tubes Contribute to Climate of Innovation Coils made with MicroGroove Tubes Allow for Lighter, More Compact ACR Products
in 2010, pioneering a new trend towards healthier home appliances. Today, Hydronic manufactures the first large scale antimicrobial copper coils air handling units in Europe, designed for off-shore, hospital, industrial and commercial applications.
In summary, there are many factors influencing the climate of innovation in the ACR industry today. These factors include
Phase out of high-ODP and high-GWP refrigerants
Smaller diameter copper tubes are contributing to a climate of innovation, according to the International Copper Association. The ICA has been highlighting the use of smaller diameter, inner-grooved round copper tubes in air conditioning and refrigeration (ACR) applications. According to the ICA, interest in ACR product design has intensified in recent years and new designs of heat pumps, air conditioners and refrigerators are flourishing. The regulation of the ozone depletion potential (ODP) and global warming potential (GWP) of refrigerants continues to challenge researchers to search for new refrigerants and challenge product designers to use natural and alternative refrigerants more effectively. Furthermore, the demand for energy efficiency has eliminated poorly designed products from the marketplace. ACR manufacturers have become highly motivated to reduce the cost of their products and one way to reduce costs is to reduce the materials content of their products. All else being equal, the highest coefficients of performance (COPs) are realized by more efficient cooling of refrigerant in the condenser and more efficient warming of refrigerant in the evaporator. Thus, energy efficient coils made from smaller diameter, inner-grooved, copper tubes are essential components in the redesign of ACR units in the new climate of innovation.
Use of Simulations
Energy efficiency standards
Heat exchanger coils facilitate two key thermodynamic processes in the vapor-compression refrigeration cycle. With the availability of more sophisticated software programs and increasing numbers of engineers proficient in modeling, a new era of design now allows for many products to be tested without soldering a single elbow joint. Software now allows for computational fluid dynamics to be combined with heat transfer calculations. These simulations can be run for different refrigerants and different coil designs, sampling a vast design space as quickly as the parameters can be changed in the software. In this manner, ACR designers can settle on optimized designs of innovative products after sampling a very large design space.
Computer simulation of components and system performance
Responsiveness to needs and wants in the marketplace
Specifically for coil design, product development will be especially influenced by the following factors:
Smaller diameter copper tubes
Inner-grooved copper tubes
Antimicrobial properties of copper in coils and air handlers
“End-users will enjoy healthy, eco-friendly products that deliver
cooling capacity with high energy
Another factor that is influencing the design of air conditioning and refrigeration systems is new published research on copper’s efficacy against the spread of fungi in air conditioning systems. ACR companies such as the Chinese airconditioning giant Chigo and Hydronic in France have already developed all-copper products expressly for their antimicrobial properties. Chigo launched the world’s first antimicrobial copper room air conditioner
it is most desirable,” says Nigel
efficiency when as well as where Cotton, MicroGroove OEM Team Leader for ICA.
For more information on MicroGroove technology, visit : www.microgroove.net.
Mono Ezstripâ„˘ Innovation Strips Out PC Pump Maintenance Cost With dwindling maintenance budgets and rising levels of difficult to handle sludges and effluents, the Water and Wastewater industry is experiencing some of its most challenging times yet. However, there are new pumping solutions available that can make a real difference. Simon Lambert, Sales & Marketing Director for NOVÂŽ MonoÂŽ, looks at how its revolutionary EZstripTM Progressing Cavity (PC) pump has been developed to help facilities meet the demands of modern wastewater treatment. Mono surveyed their customer base in the Wastewater industry to find out what common problems they were facing and found that the overriding response was that ragging has become a serious problem and is increasing in severity to the point where it can cause
serious disruptions to the efficiency of the treatment process. Our solution was the EZstripTM, which has been specifically designed to provide a quick and easy way to disassemble, de-rag and maintain a
PC pump in-situ, eliminating the costly maintenance and down time that servicing can often cause. On average, the EZstripTM can reduce the maintenance time needed to replace a rotor, stator, coupling rod and joint by up to 95%. The average time to completely strip down a pump and replace the drive train elements is usually one full day on typical sludge pumps; the EZstripTM reduces this to just a 30 minute job. By completely rethinking the design of the suction chamber and drive train element of a PC pump, we have also been able to eliminate the difficulty, time and cost of de-ragging and maintenance. The chamber of the EZstripTM has a two piece design, which can be dismantled and assembled in place and can be opened up and rebuilt with a spanner and an Allen key in a fraction of the time previously required.
For more information on the EZstripTM, contact Mono on +44 (0) 161 339 9000 or visit the website: www.mono-pumps.com.
The Past and Present of Data Logging After three decades, the data logging market is still going strong driven by new technologies, greater penetration of wireless data links and Web enabled instrumentation, says Nathan Neal of Grant Instruments.
vital constituent of the measurement market and indispensable in the research and development field for collection of physical measurement data. So what is a data logger? A data logger is an electronic device used to measure and record physical or electrical parameters such as temperature, strain, displacement, flow, pressure, voltage, current, resistance, and power over a period of time. This data is usually measured via internal or external
According to the 2011 research report titled â€˜Data Acquisition (DAQ) Hardware: A Global
sensors. Modern data loggers, driven by
Strategic Business Reportâ€™ from Global Industry Analysts, Inc., the data logging market is
latest microprocessor technology, are
forecast to exceed US$1.3 billion in 2017. Despite being around for 30 years, data loggers capable of acquiring, processing, storing and analysing data at high speeds and are continue to evolve owing to regular introduction of new technologies and are now a most commonly used in a wide range of scientific experiments, engineering research projects and monitoring systems. The first form of data logging through chart recorders was introduced in 1961, with Grant Instruments pioneering the design and manufacture of such products to monitor temperature. Paperless recording of data was soon to follow, firstly onto a cassette tape and later onto a solid state memory recorder. These recorders also had additional capabilities to record more physical parameters such as humidity, temperature (for example monitoring beer and soft drinks pasteurisation) and the higher temperatures of metal parts as they passed through paint stoving ovens. By the mid-1980s, Grant introduced the very first truly portable microprocessor controlled data logger, the Squirrel data logger, with a built in liquid crystal display.
Microprocessor technology The modern data logger is typically quite a small hand-held device with a large memory. They are powered by the latest microprocessor technology and capable of acquiring, processing, storing and analysing
A Squirrel SQ2040 portable data logger
electrical signals at high speed (up to GHz) from a wide range of sensors - at regular
DataLoggers intervals or in response to an event such as
some control functions such as activating
a threshold being crossed or a switch being
an alarm or a switch to start or stop an
Web-enabled loggers and instrumentation
ancillary piece of equipment.
are expected to dominate the DAQ market
The sensors may communicate with the
The advantage of using a dedicated
Industry Analysts report, and make it
logger through a cable or wireless link and
portable data logger compared to, say,
possible to cost-effectively manage data
may sense temperature, humidity, pressure,
a PC, is that the logger hardware and
from multiple, geographically remote
flow, wind speed, current, voltage,
software are specifically designed for
locations via a standard browser interface.
resistance and a host of other physical
stand-alone data logging applications.
This is particularly useful for environmental
in the near future, according to the Global
parameters that are important in monitoring
monitoring projects as well as for field
and controlling processes or conducting
This means that it is easy to connect and
research and field engineering, where
set up sensors and the logging system
different stakeholders require remote and
is more rugged and less power hungry,
speedy access to the very latest data.
For example, Grantâ€™s SQ2040 logger
making it capable of running on batteries
features twin microprocessors, four 24-bit
for longer periods of time, often in hostile
analogue-to-digital converters, 16 true
differential or 32 single end channels, 8 event inputs, plus USB and RS232 connectivity. It can store up to 14 million readings in the onboard memory and is powered from internal cells, an external power supply or via USB connection. Data stored by stand-alone data loggers is typically downloaded into a computer for more detailed analysis and reporting, though some data loggers have sophisticated on-board processing and analysis capability and can carry out
Wireless data links
Diverse applications Data loggers can be used in a wide spectrum of different applications in a broad range of industries. Data loggers can be
The advent of wireless communication
used for monitoring different crops inside
and networking means that it is possible
and outside of glasshouses by logging such
to both install and interrogate a logger
parameters as air, soil or leaf temperatures
remotely which can be extremely useful for
as well humidity, CO2 and solar radiation.
unattended or remote applications. These wireless communications devices can also
Other uses can be monitoring solar
be hugely beneficial by being relatively
heating systems, internal and external
simple to install when deploying site wide
temperatures, process parameters,
monitoring systems across a large facility or
water temperature and flow together with electrical consumption. Other slightly more exotic applications include logging temperature of chocolate bars passing through cooling tunnels as well as internal body and skin temperature of sportsmen in endurance or extreme environment training. Industries where data logging is commonly used include earth & life sciences, agriculture, food and water production and quality, energy production and conservation, medicine & pharmaceuticals, chemistry & chemical, work & sport activities, engineering, aviation, transport, building industry, meteorology, zoology and conservation.
Contact Grant Instruments: T: 01763 260811 www.grantinstruments.com
Nathan Neal of Grant Instruments
New Tinytag Thermocouple Data Logger Gemini Data Loggers’ Tinytag Ultra 2 Thermocouple data logger provides fast response, versatile and costeffective temperature monitoring. It supports the most popular thermocouples types – K, J, T and N – providing monitoring from -270°C to 1370°C, depending on the type being used.
The compact, battery-powered logger features burn-out response, and has a built-in temperature channel allowing the particular process and the ambient air temperature to be monitored simultaneously. It incorporates a connection that supports both standard and miniature thermocouple plugs. Data is downloaded to a PC via a USB connection and viewed with easy to use Tinytag Explorer software. From £99 + VAT. Gemini Data Loggers (UK) Ltd Scientific House Terminus Road Chichester PO19 8UJ +44 (0)1243 813000 firstname.lastname@example.org www.geminidataloggers.com
Cott – Driving A Pipeline Of Innovation! In 2003 Cott, the world’s largest retailer brand beverage company, invested in the dry lubrication systems and expertise of Dry Lube at their site in Nelson to provide their production lines with better efficiencies as well as to meet their environmental and financial targets. Long before sustainability became a matter of public interest Cott pursued a number of environmental practices to meet their strong environmental targets. The investment in dry lubrication has been a beneficial factor in achieving excellent environmental performance and commitment. At its facility in Nelson the water, energy and CO2 savings that have derived from the dry lube systems have been significant. Dry Lube reports savings of 65 Million litres of water, 750,000 kWh of energy and 400 Tonnes of CO2 since 2003. Cott company philosophy is that their success lies in the production of innovative, high quality retail brand beverages combined with world class packaging. These passions for innovation lead them to invest in the Dry Lube lubrication systems in order to enhance environmental performance and reduce costs. At present, Cott uses dry lubrication on 4 PET bottling lines at its facility in Nelson. Simon Knaggs, Site Engineering Support Manager comments on Dry Lube’s system and service: “We are satisfied with the system that apart from water savings delivers benefits such as less fallen bottles and better production flow. We receive good skills and knowledge from their engineers and are especially happy with the call out response we have if an issue might occur.” Cott is the leading supplier of private label carbonated soft drinks distributing to over 50 countries around the world. It engages in producing packaging and distributing beverages all over the world serving a host of grocery, mass merchandise and drug store chains and whole sale and convenience chains. The ever expanding product line now includes its own brands in many new drinks such as ready to drink teas, sparkling and flavoured waters, sport and energy drinks, juice drinks and smoothies.
Wind Turbine Maintenance
Bolt Tensioning on Wind Turbines Considerations when choosing bolt tensioning tools Bolting on Wind Turbine Towers Bolt tensioning is vital to the integrity of wind turbines. As well as being extremely important for applying accurate bolt loads, efficiently and safely, it is also a consideration both for the builders and installers of the turbines, as well as the maintenance engineers who are required to carry out regular bolt load checks. This article will look at why accurate bolt tensioning is important, particularly for the foundation bolting in USA and Canada and what aspects are important when choosing the right equipment for the job. Where Bolt Tensioning is Required There are 8 main areas where bolt tensioning is needed on a wind turbine. As illustrated in Photo1, from the foundations upwards, different parts of the wind turbines have to be safely put together. Due to their size, the turbine towers are transported to the installation site in pieces and then assembled. Throughout Europe and the rest of the world, the bottom section of the tower is cast into the concrete foundation and the lowest section is then welded on site. However, North America and Canada have a unique system. Here, a foundation laying company lays the foundations, concreting the bolts into the ground. After the concrete is set, the turbine towers arrive on site and are simply lowered over the bolts. Hydraulic Bolt Tensioning for Foundations Hydraulic bolt tensioning is now recognized as the standard and preferred method for securing wind tower sections, particularly the foundations. This is due to the fact that foundation bolts can be up to 20ft long and it is not feasible to use hydraulic torque wrenches as this would add twist to the bolt rather than the elongation required. Elongation on these larger bolts can be up to 1â€? and therefore tensioners have to be used to stretch the bolt.
Installing Wind Turbine Tower Foundations in the USA and Canada A reinforcing steel bar (rebar) bolt is used in foundation bolting applications, as the threads used in the rest of the world would get damaged during this process of concreting them into the ground. These bolts are similar to those used throughout the construction industry and manufactured to tolerances and standards required to meet the exacting safety requirements of the industry. The use of these rebar bolts means that foundation bolting applications have different requirements from, for example, blade bolting. As the rebar bolts are manufactured in softer material than the blade and tower bolts, this means that they will stretch more and the extensions will be longer. In light of this unique foundation system, specialist hydraulic bolt tensioning equipment is needed. So what should companies look for when evaluating such equipment?
Wind Turbine Maintenance
Choosing the Right Bolt Tensioning Equipment for Foundations In general, two designs of bolt tensioners are available and
Photo 3 shows an example of a long and short stroke tensioner. As the amount of thread protruding from a foundation bolt can vary enormously from turbine to turbine, many
the choice depends on two factors. The first is dependent
contractors will carry both tools to ensure they have the
on the length of the bolt, which determines the amount
correct equipment for each and every job.
of elongation needed and the other deciding factor is the amount of stud protrusion above the tower base flange. Due
to the fact that the foundation bolts are concreted into the ground, the protrusion cannot be precisely controlled.
Safety is paramount in all construction jobs and when looking for foundation bolt tensioning equipment, safety
Therefore, contractors need to determine which is the
features must be properly assessed. One of the most
most appropriate tool for the job. A short stroke tool, as
important features to be considered is to ensure that there is
the name suggests, is used when the stretch needed is up
overstroke protection as an integral part of the tool. Without
to 3/8” and the protrusion is a minimum of 7.5”, whereas a long stroke tensioner can achieve an elongation of up to 1” on a minimum protrusion of 10.5”. For speed and efficiency, combined with ease of use for the engineer, these tensioning tools should also allow for “one pull” uninterrupted tensioning. This enables the longest of bolts to be stretched in a single operation. If only a short stroke tool was available for one of the larger bolts, then the tensioning
this feature, engineers are prone to keep stretching and the seals will fail. Once this occurs, the operation has to be stopped as the seals have to be replaced. This results in costly downtime that could be crucial for a profitable on-site job. Avoiding Overstroke
would have to be carried out in two or three different steps. Manufacturers of bolt tensioning tools are mindful of the overstroke problem and have incorporated some form of protection in their tool sets. The latest technical advance in this area is a unique positive mechanical stop system. This failsafe system has been designed so that just fractions of an inch over the required extension and engineers will hit a mechanical stop and stretching will cease. Versatility for all types of bolts Another important aspect to consider is the different types of rebar bolts that are used throughout the industry. In the past, the standard construction bolt was the Grade 75 ksi, accounting for approximately 90% of applications. Now, a 150ksi rebar is becoming increasingly common and recently, a new Grade 90 ksi bolt has been developed for the wind industry. This new all-thread rebar allows for higher levels of design stress or designs with less anchors for critical applications such as wind energy foundations than other conventional types of rebar. Tensioning tools must be versatile enough to handle all three types of rebar.
Wind Turbine Maintenance
Space Restrictions and Accessibility In addition to the long and short stroke bolt tensioners, contractors will also need to bear in mind space restrictions and accessibility. Elliptical tensioners have been developed that help overcome these problems. Most have been designed with a width reduction, so they can fit and operate in situations where space is limited, often found while tensioning inner bolts when they are close to the tower wall. Streamlining Operations Also, engineers should look for other features and benefits that can streamline operations. To increase speed, some tensioners are fitted with a spring mechanism that automatically resets the tensioner once the pressure has been released to zero. This means the tensioner is then ready to tension the next bolt, with no operator intervention required. In order to further streamline operations, multiple tensioners can be linked together with high pressure, flexible link hoses to give simultaneous bolt loading. Most contactors only use one tensioner at a time, but by using 2 tensioners, 180ยบ apart and attached to one pump unit, more even tensioning can be achieved and when there can be up to 100 bolts to tension, this technique will also save a considerable amount of time. In an industry where time is money, payback on the original purchase price can be achieved quickly. Conclusion Due to the unique foundation system in the USA and Canada, particular considerations have to be taken into account when choosing bolt tensioning equipment. Specialist tensioning tools are available that will ensure the integrity of the tower and make installation and ongoing maintenance an efficient and safe process. Author: Roy Sheldon. Tentec Ltd. Plymouth House. Guns Lane, West Bromwich, West Midlands B70 9HS. Tel: + 44 (0) 121 524 1990 Fax: + 44 (0) 121 524 1999 E-mail: email@example.com
Thermal Imaging Key To Maintenance Strategy, Says Brammer A thermal imaging device is an invaluable addition to any maintenance toolkit.
up a picture of what things look like in normal operating conditions and spot when a component is generating excessive heat.” Organisations may save time and money with an effective condition monitoring programme. Observing the manufacturing process provides insight into the lifespan of key components and assists planning for their replacement. Thermal imaging is the latest topic covered by Brammer’s ‘Quick Tips’ Video series; succinct visual aids presented by product group specialists and industry experts, to explain key issues and suggest practical advice for customers. The latest Quick Tips video on thermal imaging is now available online at www.brammertips.com.
That’s the message from Brammer,
“Running hot is usually a tell-tale sign
Further information on the
the leading pan-European distributor
that a component is about to fail,” said
range of products and services
of industrial maintenance, repair and
Jeremy Salisbury, Head of Marketing
overhaul (MRO) products and services.
at Brammer UK: “Thermal imaging technology is really easy to use, you
available from Brammer can be found at the website:
A thermal imaging device is a quick
can see the results real-time with the
and easy way to identify potential
parts in situ - there’s no need to stop
www.brammer.biz or by calling
problems before they become the
the manufacturing process.”
08447 36 36 65 in the UK or
cause of major and costly breakdowns.
0181 77 6141 in Ireland.
It’s the fastest growing preventative
“We’d recommend that all customers
maintenance technology, ideal for use
include thermal imaging in their
with any type of machinery.
routine maintenance. You soon build
New Loctite Instant Adhesives Built To Take The Heat Loctite instant adhesives for industrial applications already encompass a broad range of different categories, such as light-curing, low-bloom, impact and shock resistant, as well as toughened products for flexible bond lines. Loctite instant adhesives are also
service temperatures of up to 120 °C.
extensively used for joining difficult-
All three products have seen their
to-bond plastics, for gap-filling
formulation improved and are now
applications and in medical devices.
temperature resistant up to 120 °C
Now, with Loctite 401, 406 and 454,
without any adverse effect whatsoever
three products with an enhanced
on overall performance – which means
Loctite 401, 406 and 454 can fixture
formulation have been launched onto
these Loctite instant adhesives are
almost any material in less than five
the market, capable of withstanding
suitable for even more applications.
seconds. They are exceptionally reliable
The three new Loctite instant adhesives with their improved formulations.
and safe to use – and now they can withstand higher temperatures than ever before. They can be readily integrated in all kinds of production processes or used in the workshop, invariably contributing to both efficiency improvements and savings in cost. These products are available in various viscosities to suit individual user applications, and there is also a comprehensive range of dispensing equipment available. New fields of application for Loctite’s proven instant adhesives New applications for this improved product range can be found, for instance, in the electronics industry, Ideal also for bonding jobs in the engine compartment: new Loctite 401
e.g. for bonding components installed in generators and storage batteries. In EMS Magazine
Adhesives electric motors and loudspeakers too,
The multi-purpose instant bonding gel
the number of uses for these enhanced Loctite adhesives has been extended.
Loctite 454 is a general-purpose instant bonding gel that does not drip, making it
And also in washing machines and
ideal for applications on vertical and overhead surfaces. It will bond paper, wood,
tumble dryers, in heating elements
cork, foam, leather, cardboard, metals and plastics.
and lighting equipment, the upgraded
Until now its service temperature lay between –40 °C and +80 °C. Now, with the
product line should soon find itself
improved formulation of Loctite 454, service temperatures of up to 120 °C are
increasing in popularity.
likewise possible, which means a huge expansion in the range of applications for which the gel is suitable, not to mention the boost in confidence that naturally
Some interesting applications for these Loctite instant adhesives are shown in a video on the website: www.loctite-instantadhesives.com.
occurs where the service temperatures are at or around the previous limit of 80 °C. Quick and easy production upgrades Customers can continue using their already installed dispensing equipment to apply the new adhesives. Conversions take no time at all as the product containers are unchanged. Consequently, new applications can also be
New product capabilities Loctite 401 is the all-purpose instant adhesive. It is as suitable for rubber,
implemented with all three products without problem. Loctite 401 and Loctite 406 are available in 20 gram, 50 gram and 500 gram bottles, while Loctite 454 instant adhesive gel is sold in tubes of 3, 20 and 300 grams.
plastics and metals as it is to bonding porous materials such as wood, paper, cork or leather. It is also ideal on smooth, acidic substrates, for example
Henkel operates worldwide with leading brands and technologies in three business areas: Laundry & Home Care,
galvanized or chromated components.
Cosmetics/Toiletries and Adhesive Technologies. Founded in
In less than five seconds, this clear
1876, Henkel holds globally leading market positions both in the
adhesive reaches its initial fixture strength, enabling any temporary
consumer and industrial businesses with well-known brands
clamping or securing means to be
such as Persil, Schwarzkopf and Loctite. Henkel employs more
removed from the mating components.
than 47,000 people and reported sales of 15,605 million euros
Offering similarly improved formulations, the new instant adhesives Loctite 406 and Loctite
and adjusted operating profit of 2,029 million euros in fiscal 2011. Henkel’s preferred shares are listed in the German stock
454 can likewise withstand elevated
index DAX and the company ranks among the Fortune Global
temperatures of up to 120 °C.
Loctite 406 is particularly suited to the bonding of rubber, plastics and elastomers. Following surface
treatment of with the polyolefin primer
Loctite 770, even substrates made from polyethylene, polypropylene
Phone: +49 211 797-99 33
and polytetrafluoroethylene (PTFE)
Evelyn Necker +49 211 797-56 72
can adhesive-bonded. This clear,
transparent product reaches its initial fixture strength within two to ten seconds.
Production Best Practise
Improving The Production Process Through Closed-Loop Tension Control Web tension effect is achieved when opposing longitudinal forces are exerted on any substrate (e.g. paper, film, board, cable). Experts in the converting and printing processes know how critical good tension control is to their process and that tension can represent a single point of failure during production. Accurate and stable tension control on driven material ensures: • • • •
tension controllers – dancer mechanisms and electrical load cell transducers. Colin has been part of Optima’s engineering team since 2007. Web transport applications are among his specialist disciplines. With more than 19 years of control systems engineering experience, Colin talks here about the two closed loop web control systems from a practical point of view.
Higher quality product Less scrap and, therefore, improved productivity Higher production speeds Improved downtime and lower operating costs
Good web tension control systems ensure that no matter how demanding the production process is, the correct web tension is maintained for any type of material, at any point of the machine and at any speed. Open Loop vs. Closed Loop Web tension control - What is the difference? In an open-loop control system there is no direct tension feedback signal so controlled corrective action for any web tension variance is not possible. They operate on a predictive load basis. In contrast, a closed loop tension system uses a signal (generally an electrical one) that is proportional to the position of a feedback transducer (i.e. load cell or dancer mechanism) that is pre-tensioned as determined by the main process requirements. The control system uses a PID controller (proportional, integral and derivative controllers are essential elements in a tension control system but fall outside the scope of this report) There is a cost-performance payoff between both alternatives; high performance closed-loop systems provide accurate, consistent tension control. Colin Keating, an experienced design engineer at Optima Control Solutions Ltd., talks further about two popular types of closed-loop
[Colin, in the tables above you have summarized the pros and cons of both dancer rolls and load cells. Are dancers easier to maintain for maintenance engineers on a production site?] Not necessarily. Load cells are mechanically simpler than dancers. The only moving (wearing) part on a load cell is a bearing that it is quite easy to replace. With a more complex dancer system, in contrast, one needs to maintain whatever the pivot point is (whether it is a cylinder, or chains and weights). Another more technical issue that occurs in dancer systems is the inherent non-linearity of the feedback signal that the mechanical experts need to consider in their designs. The mechanical parts must not tighten the web. [Can you recall any particular projects that you have engineered involving dancers?] The most impressive project I can think of is one that we supplied to CCL Decorative Sleeves in Kings Lynn. Their printing machine had a flying splice winder section. (Please, scan the QR code to access the flying splice winder video). I remember it because in short, someone had removed the original dancer mechanism (it used weights) and replaced it with a load cell arrangement believing that the load cell would provide better accuracy. The machine would then only splice for 1 out of 3 attempts; clearly
Production Best Practise one reason why they get in touch with us; increasing production speed is another. We have completed projects that involve a straightforward control system upgrade through to more mechanically complex projects where we have removed existing line shaft arrangements and introduced individual section controls providing faster setup times and much better flexibility for the operators.
unsustainable. They contacted Optima for our advice. Experience told us that the application needed a dancer mechanism but in a much more modern arrangement. The difficulties in using load cells on a flying splice were then all too apparent to CCL.
various sections on a machine. If the web is transported or wound at too low a tension it can wander from side to side causing process problems (e.g. print registration issues) or poor winder performance (the so-called “telescope” phenomena).
CCL found that when switching the tension control from one roll to the next one, in the splicing sequence, the whole control system was disturbed within a fraction of a second and using the load cell meant it lost tension. We engineered a new dancer system with very low friction components and achieved reliable splicing for them with ease.
Conversely, too much tension can deform a substrate or cause problems on the surface of the material.
Most of the flying splices we have done have dancers because of the accumulation advantage mentioned above. If a load cell is used for this type of process, the disturbance created by other splicing component rolls and knifes can easily cause the web to jump off the roll. The dancer absorbs the shock and allows the control system to overcome the short disruption. [What about load cells? What circumstances necessitate their use?] Certain pieces of equipment need the material to be at a guaranteed tension. A printing press, for example, will need accurate and stable tension control. A print register system ensures that all the colours are printed accurately with respect to oneanother It will only work well if the substrate being printed on is stable and running at the correct tension value. The printer will need to control his substrate flexibly and accurately to accommodate different materials. Another common requirement is for the tension levels to be different for
One obvious advantage using load cells is their operational flexibility. Operators change the web tension simply by changing a number on a HMI or a potentiometer dial. It is possible to make adjustments to dancer system in a similar way using E-P transducers, but still the whole system is not as flexible. [What are the recent technological developments for load cells?] At present, load cell technology is so widely developed that dancers have become the more costly solution. Also, in applications where low web tension is required, dancers are not suitable – dancers contain inherent mass and inertia that the web must overcome. The most significant innovation on the load cell control technology is the shift towards digital controls. The latest load cell amplifiers employ intelligent tuning techniques and digital communications networks (e.g. ProfiBus). [What are the typical web tension control issues of our customers?] Our clients experience a range of issues. Improving process and machine reliability is
The majority of our customer applications use load cells, not dancers, though understanding which applications necessitate the use of one or the other (or a combination of the two technologies) means we still employ dancers where the process requires. This is where Optima have a great deal of expertise and experience. As per our example, a butt splicer might work easily with a load cell system but it is a different story for flying splice winders, this type of knowledge is critical to a projects success. Disclaimer: All the information provided in this article is for informational purposes only. Opinions expressed in this report are those of the relevant contributors. Reproduction and citations are allowed after appropriate referencing of the full report at http://www.optimacs. com/download_optima_reports. aspx Optima Control Solutions Ltd. reserves the right to deny use of this report on third-party websites and in third-party publications. Images sourced from: Optima™ gallery – all copyrights reserved. Design: Gimp www.picnik.com Written by: Hristina Stefanova Revised by: Michael Hill
Sherborne Sensors’ Inclinometers Support Ruag Space In Life Test Qualification Of Thruster Orientation Mechanism Customised to withstand extreme changes of temperature under hard vacuum, Sherborne Sensors’ precision servo inclinometers offered precision performance throughout threemonths of life test qualification to help RUAG Space successfully complete rigorous testing of its innovative satellite Thruster Orientation Mechanism (TOM). As the largest independent supplier
satellites employ RUAG’s structures,
of space technology in Europe,
with well-known examples being the
RUAG Space is well known for its
primary deployment mechanism of
precision mechanisms for pointing,
the solar array for the Hubble Space
deployment and high-performance
Telescope, the separation system of
separation in spacecraft applications.
the Huygens Probe from the Cassini
Most European Space Agency (ESA)
Spacecraft and the electrical propulsion
pointing (EP) mechanism for the SMART-1 and Artemis satellites. Pointing mechanisms and EP thrusters are used by commercial satellites for moving from launch orbit into their real orbit and to perform micro-positioning manoeuvres. RUAG has developed a new type of thruster orientation mechanism (TOM) that simplifies the overall design of a satellite by having two TOMs instead of the eight stationary thrusters units employed in conventional designs. Each TOM features one or two thrusters mounted on a gimbal structure and is powered by actuators. Able to support the largest range of thruster combinations and thruster mass in the market today, RUAG’s TOM means only a quarter of the normal amount of Xenon tubing is required to supply fuel to the EP thrusters. The nature of RUAG’s TOM design means it has to accommodate the environmental loads induced during launch and spacecraft separation from the launch vehicle, as well as the extreme of temperature experienced in space. It has therefore been subjected to a design qualification test programme that entailed a series of rigorous functional and performance tests in order to demonstrate and verify its performance against everything it can reasonably expect to experience from manufacture through mission to
end-of-life, which could be ten years or more.
on the TOM qualification model in order In a high vacuum environment, the to perform three key tests – mechanical outgassing of organic compounds pointing accuracy, potentiometer
such as adhesives and rubber can
verification and motor margin. Tests
destroy the vacuum conditions and
were conducted in a large vacuum
potentially ruin the tests. Sherborne
In order to meet the rigours of RUAG’s
chamber, where an extremely low
Sensors was therefore careful to ensure
lifetime qualification tests, a special
pressure of 10-7 mbar is achieved.
that the inclinometer did not contain
variant of Sherborne Sensors’ LSI
Known as a ‘hard vacuum’, this
any compounds that would suffer this
Servo Inclinometer was developed.
simulates the in-orbit environment.
deficiency. In addition, to counter the
Rigorous qualification testing
effect of differential pressure between
The LSI Servo Inclinometer is a selfcontained, precision gravity-referenced servo inclinometer and was mounted
“Finding measurement devices capable the sealed case of the inclinometer and the vacuum conditions it was being of operating at this very low pressure is not easy to do,” says Andrew
used in, the case of the inclinometer
Skulicz, AIT Engineer at RUAG Space.
was provided with a vent to allow the
“But having discussed our design
internal volume to assume the same
requirements with Sherborne Sensors,
pressure as the external conditions.
we were able to ensure that their inclinometers fulfilled our requirements.
“These customisations ensured that
The most important aspect was that
there was no danger of any minor leaks
they were able to operate between
destroying the high vacuum conditions
-40°C and +40°C under hard vacuum
over time, as well as relieving any
conditions. Only Sherborne gave us the mechanical stresses that could occur during de-pressurisation,” says Mike range that we wanted, together with the accuracy.”
Baker, Director at Sherborne Sensors.
Sensors cooperative, providing strong technical
“The LSI was also characterised for performance over the applications
“Such tests were arduous for both
support and we worked together really
operable temperature range to give
the mechanism and the inclinometers,
well to ensure that this part of the
a high degree of accuracy. Because
given that it was necessary to detect
programme ran smoothly,” Andrew
RUAG had the ability to correct for
if the motor looses steps with an
thermal errors within its data acquisition accuracy of at least 0.01°,” says algorithms, we also provided them with Andrew. “Additionally, tests were a ‘look-up’ chart listing the individual
carried out at extreme positions (+34°)
About RUAG Space
temperature errors over the complete
to further test the performance of the
As the largest independent
range of environmental temperatures
inclinometers over their full range. The
expected to be met in the application.
inclinometers on the TOM not only
This enabled RUAG to correct in real
successfully operated throughout a
time for the effects of temperature and
sequence of thermal vacuum cycles,
launch vehicles. From our locations
deliver more accurate results.”
but also sustained that operation
in Switzerland, Sweden and Austria
for nearly three months while the
RUAG’s space division offers a
Customised inclinometer solution
mechanism was undergoing its life
comprehensive portfolio of products
delivers qualified success
For mechanical pointing accuracy, the
According to Andrew, the fact that
inclinometers were used to measure
the pointing performance of the
a long lasting partner of choice
the pointing vector of the TOM with
mechanism did not change throughout
for satellite and launcher primes
respect to a reference frame, with
the programme while the variation in
accuracy to higher than 0.05° being
motor margin at different temperatures
essential. “The inclinometers were
was clearly visible showed that the
used to measure and characterise how inclinometers were sensitive and
supplier of space technology in Europe, RUAG Space develops, manufactures and tests subsystems and equipment for satellites and
and services for institutional and commercial space missions. Heritage and flexibility as well as outstanding reliability have made RUAG Space
About Sherborne Sensors Sherborne Sensors is a global
the pointing vector of the mechanism
able to perform well under extreme
varied in different thermal conditions,”
temperature and thermal vacuum
manufacture and supply of
continues Andrew Skulicz at RUAG
conditions. “I could also be confident
high precision inclinometers,
the inclinometers performed all the
accelerometers, force transducers
way through the test programme as
and load cells, instrumentation
The performance of the potentiometers expected, because the inclinometers
leader in the design, development,
and accessories for industrial, military and aerospace customers.
was also checked under different
measure pointing accuracy, which
thermal conditions to ensure they
is based on gearbox geometry
could return accurate telemetry
and should remain constant. It’s a
and are renowned for their ultra
back to the spacecraft, while motor
bit of a circular reference, but this
reliability and long life precision within
margin tests were conducted to
substantiates the fact the inclinometers
critical applications. The acquisition
verify that the performance of the
didn’t degrade during the test.”
of synergistic technologies by
on-board stepper motors did not
Products are supplied under the AS9100B Quality Accreditation
Sherborne Sensors within its product portfolio has allowed customers to
degrade. The inclinometers were
RUAG’s TOM programme represents
used to verify the performance of the
the cutting edge of the European
potentiometers over the full angular
scientific community, with the test
support, global sales presence,
range of -14°/+34°, with the required
results having been approved by ESA.
repair, refurbishment and calibration
accuracy being better than +/-0.05°.
“This is not easy to obtain and requires
services, stocking programmes and
The inclinometers were removed during that we are able to substantiate that vibration and shock testing however, as the results are valid. The team at they would have been damaged.
Sherborne Sensors has been very
benefit from expanded product lines, with added benefits of engineering
continuous product improvement. For further information go to www. sherbornesensors.com