ISSUE 73 2021
Specialising in stainless steel and its applications
Photo credit: J & T Mechanical Installation
FEATURE
Raising the standard WITH STAINLESS STEEL Water quality plays a crucial role in the decontamination and reprocessing of reusable medical devices, and stainless steel has helped facilitate the standard required for their sterilisation. The release of AS/NZS 4187:2014 Reprocessing of reusable medical devices in health service organisations requires hospitals across Australia to comply with a range of stringent new requirements consistent with European and global standards for sterilisation processes. Its aim is to ensure reusable medical devices are adequately cleaned, disinfected and sterilised to protect patients and prevent infection. Water quality is critical for sterile processing, and one requirement of the revised standard includes the replacement of non-compliant cleaning, disinfecting and sterilising equipment. There are minimum water quality requirements for pre-cleaning, cleaning and the rinse(s) prior to final rinsing. These include water hardness no greater than 150 mg/L and chloride no greater
than 120 mg/L. AS/NZS 4187:2014 also specifies water quality requirements for the final rinse stages of sterile processing across Tables 7.2, 7.3 and 7.4, including final rinse water for manual cleaning and washer-disinfectors, and feed water for a dedicated steam generator. Despite the Australian water quality guidelines, water supplies are variable in chemical impurities and the microbiological purity may also be a challenge. Therefore, water used for the final rinse of the disinfection process and the generation of steam for sterilisation must undergo treatment to achieve the water quality requirements. Reverse osmosis technology delivers a solution to meet the physical, chemical and microbial water quality required for the final rinse.
Stainless steel is the standard material of construction in water treatment applications, offering hygienic properties, durability, and optimum long-term performance.
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Photo credits: J &T Mechanical Installation
Reverse osmosis (RO) is a water treatment process that uses a semipermeable membrane and applied pressure as the final step to filter out ions, unwanted molecules and large particles. The process is effective for the removal of micro-organisms and both organic and inorganic chemical components. ASSDA Member and Accredited Fabricator J&T Mechanical Installation have delivered stainless steel bioprocessing equipment for over 25 hospitals across Queensland, New South Wales and Victoria to meet the new specification and requirements of AS/NZS 4187:2014. The ongoing work includes the fabrication and installation of new equipment and replacement of non-compliant ring mains, water distribution networks and RO water treatment systems.
The RO water treatment systems must accommodate the required regular thermal disinfection to mitigate bacterial endotoxins and deliver a high level of microbial water quality. The treated water is reticulated to central sterile services departments (CSSDs) where surgical instruments and other reusable medical devices are sterilised. Continuous bacteria control is critical to supplying the required microbial water quality and the use of ultraviolet (UV) light in the ring mains to treat return water delivers compliance with AS/NZS 4187:2014. UV sterilisation is 99.99% effective in killing microbiological substances, and is a safe, chemical-free process. Stainless steel is the standard material of construction in water treatment applications, offering hygienic properties, durability, and optimum long-term performance. With excellent corrosion resistance and hydraulic conductivity characteristics, stainless steel is the first-choice material for best overall water system design. In addition, plastic materials are not viable in high water purity applications due to potential leaching, and copper may also be an issue because of cupro-solvency in soft water. Grade 316 stainless steel material has been specified for works as per the standard, including the use of 51mm tube, 20mm three-piece ball valves, and 45o and 90o bends as specified in AS 1528 and supplied by ASSDA Member Atlas Steels.
J&T Mechanical Installation’s expertise has ensured the highest quality of work continues to be delivered to meet the current and future requirements of water supply systems complying with AS/NZS 4187:2014. Orbital welding is used on site during installation, with bioprocessing equipment requiring high quality welds to ensure water supply remains free of bacteria, rust and other contaminants. Orbital welding ensures full penetration welds with no overheating occurring that could undermine the corrosion resistance of the final weld zone. The J&T team also performs hydrostatic testing and weld traceability to confirm mechanical integrity, as part of AS/NZS 4187:2014’s requirement for all equipment to undergo installation qualification (IQ), operational qualification (OQ) and performance qualification (PQ) tests. As the roll out of AS/NZS 4187:2014 continues across Australia, hospitals and other health organisations are required to have a documented plan for implementation in place by December 2021, with the deadline for full compliance by December 2022. Critical hospital infrastructure demands long-term compliance, structural integrity and quality fabrication, all of which are being delivered using stainless steel and superior workmanship by J&T Mechanical Installation.
With excellent corrosion resistance & hydraulic conductivity characteristics, stainless steel is the first-choice material for best overall water system design
ASSDA MEMBER CONTACTS Atlas Steels \ Tracey Koplick, Internal Sales Supervisor \ 0409 077 782 \ tracey.koplick@atlassteels.com.au \ atlassteels.com.au J&T Mechanical Installation \ Trent Todd, Director \ 07 5534 4499/0438 796 314 \ trent@jtmgroup.com.au \ jtmgroup.com.au
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TECHNICAL
Common misconceptions about stainless steel
Everyone knows that stainless steel resists corrosion, but beyond that, an amazing range of half-truths and exaggerations have evolved - often misleading and sometimes simply wrong. This article examines some of the more common myths, explains why they are wrong, and more to the point, provides correct information.
FACT: There are hundreds of stainless steels from high strength duplex 2205 There are only two types of stainless steel, 304 and 316.
supporting bridges, to furnace ducts of ferritic 3/5Cr12 and the high temperature 310, but the most common types are the austenitic 300 series. Stainless steels were invented a little over 100 years ago. The corrosion resistance, ease of cleanability, and bright appearance of stainless steels meant its compound growth since 1950 has been about 5% year-on-year. Because of the ease of forming and welding, about 70% of stainless steel use has been within the austenitic family. Within 30 years the accepted chromium level for good corrosion resistance settled at about 18% and “304” was born. Then stainless moved to the seaside and corroded, which led to the development of “316” by adding molybdenum. This in turn created the popular myth of two readily weldable and formable stainless steels despite the hundreds of austenitic grades recognised in standards. About 25% of global use is seen in (mainly) thin sheet ferritics for cladding. The remaining 5% sees strong duplex, extra strong martensitic blades and wear resistance, and the precipitating hardening grades where strength/hardness is the priority.
FACT: Seawater has about 20 times the chloride level that 316 can withstand and it is 316 stainless steel is a marine grade and is suitable for seawater immersion.
worse if the surface is rough or has a crevice (such as a nut and bolt). Seawater suitable stainless steels are the super austenitic or super duplex grades. 316 is often referred to as the ‘marine grade’ but this simply means that, provided it has a good finish and is washed by rain or under a proper maintenance regime, it will remain bright and shiny. In seawater it will rust especially around hard fouling or crevices – think seashells or bolts – and even under deposits in the splash zone. Furthermore, in severe coastal applications where salty ocean spray is allowed to build up over time, 316 can visibly corrode.
FACT: Carbon steel contamination or choosing the wrong grade of stainless steel are If it has rust stains, it is not stainless steel.
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the usual reasons for rust on stainless steels. If the rust occurs within a few days or weeks, it is almost certainly due to carbon steel contamination from fabrication or the local environment. Longer initiation periods arise from surfaces that are too rough, aggressive environments (think 304 posts on a wharf), lack of washing (drainpipes under eves) or bar product that has not been passivated.
Stainless steel reinforcement will cause accelerated galvanic corrosion of carbon steel reinforcement.
Only nonmagnetic stainless steels have good corrosion resistance.
Low nickel in stainless steels means it will corrode.
FACT: In concrete, carbon and stainless steels have similar galvanic potentials. Galvanic interactions occur between connected metals that have different potentials when immersed in a liquid that will cause one of them to corrode. Hence 304 bolts in a 316 panel immersed in tap water will not show galvanic effects despite the difference in potentials. In contrast, carbon steel will corrode more rapidly when coupled to copper or stainless steel in water. It is different in alkaline concrete as both stainless and carbon steel are at the same potential. It is common practice to use stainless steel reinforcement in tidal and splash zones or around penetrations and couple it to the rest of the carbon steel reinforcement.
FACT: Magnetism is not related to corrosion resistance. Probably because the lower chromium stainless steels are all magnetic, e.g., the 3/5Cr12 utility grades or the 410 or 420 or 440 martensitic, a myth perpetuated that magnetism and corrosion resistance were related. And then along came duplex grades with their resistance to seawater (and more aggressive environments) plus a strong ferromagnetic effect. The weak magnetic effect of heavily cold worked 304 versus the negligible magnetic effect of cold worked 316 may also have contributed to the myth.
FACT: Nickel only affects the microstructure form, NOT corrosion resistance. Nickel is a friendly metal and is the predominant influence in turning ferritic stainless steel into austenitic or duplex grades depending on how much nickel is added. It has no effect on corrosion resistance to initiation of corrosion, which is how the integrity of stainless steel is judged.
FACT: Maintenance is important for the long-term effectiveness of any product. Stainless Well-polished stainless steel does not require maintenance.
steel requires minimal maintenance but relies on preserving its passive film with oxygen and water.
Using a 316 nut on a 304 bolt stops galling of fasteners.
FACT: Austenitic stainless steels are widely used for corrosion resistant bolting, but
Maintenance of stainless steel is required i.e., cleaning to remove adherent deposits left after rain washing. High polish will ease maintenance cleaning, but in the long term, general grime can accumulate just like the detritus on coatings or concrete.
galling control requires consideration beyond materials selection, including hardness, design and quality control, lubrication and friction. Galling of fasteners is simply the cold welding of clean stainless steel surfaces under load. It is worse with fine threads, tight clearances, poor profiles, lack of lubrication, accumulated dirt and over-tightening. Because 304 cold works more than 316, the rule of thumb that a 50HB difference in hardness would prevent galling leads to the 304 cold rolled bolts and 316 machined nuts combination as a “solution”. It may work but the list of caveats above shows its limitations.
FACT: The initial capital cost of stainless steel material may be a few percent more but, when Stainless steel is expensive.
considering life-cycle costing, stainless steel delivers long-term performance with minimum downtime and low costs associated with maintenance. Using stainless steel does not require coatings, has reduced maintenance requirements compared to repainting or patch repairs of coated or galvanised steel, and can either be repurposed or recycled after its practical life. For example, replacing galvanised steel with 304/316 stainless steel in one particular wastewater treatment plant reduced downtime for refurbishment or replacement from 22% to a mere 2%. There is a stark contrast between the maintenance of iconic structures built from different materials. The Eiffel Tower in Paris was constructed in iron and Sydney’s Harbour Bridge is the world’s largest (wrought) steel arch bridge, but both structures require regular repainting as part of essential maintenance. New York’s Chrysler Building is clad in stainless steel and has only required two washings in its 90-year history.
Contact us for more information on these facts and much more!
The Schaffhausen Bridge in Switzerland was built in 1995 with duplex reinforcement in the lower 7.6m of the pylons and 304 in the longitudinal reinforcement because of concerns about road de-icing salts. A life-cycle costing over 80 years showed that with stainless steel used for about 5% of the steel tonnage, stainless steel delivered 13% lower life-cycle costs over carbon steel. Looking at sustainability, the Tokyo Water Authority reduced leakage in their potable water distribution system from 15.4% in 1980 to 3.6% in 2019 primarily by replacing mains to meter connections with corrugated stainless steel tube. To put this into context, since 1994 Tokyo has reduced annual water leakage by nearly 142 million cubic metres, with savings in excess of US$200 million per year. 5 – Australian Stainless Issue 73
TRANSPORT
Photo credits: Callington Haven
Rejuvenating stainless steel passenger railcars
1934 marked the birth of the world’s first stainless steel passenger railcar in the United States, and today it represents over 80% of all passenger railcars in Australia. Stainless steels deliver a sustainable materials solution for the rail industry, offering excellent physical properties including formability and weldability, in addition to its high strength, durability and aesthetic appeal. The typical lifespan of a passenger railcar is 30 to 35 years, however with a proper maintenance program, stainless steel railcars can last more than 50 years. While only requiring minimal maintenance, dirt and other surface contaminants from daily use can affect the appearance of stainless steel. ASSDA Member Callington Haven was recently engaged in Sydney to rejuvenate 20-year-old stainless steel passenger railcars back to their original aesthetic using a pickling process. Pickling is a chemical treatment process applied to the surface of stainless steel to remove contaminants and assist in the formation of a continuous chromium-oxide, passive film. The process leaves a slight matt finish and provides a passive surface immediately upon rinsing, maximising the ongoing
performance, durability and corrosion resistance of stainless steel. With a controlled application and wash down process in place, the stainless steel passenger railcars’ transformation was performed using Callington Haven’s own S-Weld SPS Pickling Solution. Following pre-cleaning of the surface with a detergent, the product was applied with a roller to prevent atomisation of the pickling product. After 25 minutes, the solution was soft water blasted and excess pickling agent was removed with a squeegee. A full water blast using clean potable water and dry down of the stainless steel passenger railcars completed the process. S-Weld SPS Pickling Solution conforms to ASTM A380 (Standard Practice for Cleaning, Descaling and Passivation of Stainless Steel Parts, Equipment and Systems) and has a unique red colouring,
allowing operators to know exactly where the product has been applied or if it has been washed down properly. Pickling solutions usually employ dangerous acids, therefore personal protective equipment was worn by all personnel. For environmental reasons, measures to ensure prevention of run off onto the ground from the application and wash down of the railcars was implemented. Maintenance is key to preserving public transport and using a pickling process that only took 1.5 hours to perform, Callington Haven delivered an ‘as good as new’ end result for Sydney’s stainless steel passenger railcars. You can view this story’s pickling process in action at www.youtube.com/ watch?v=CV64kea2pBE
ASSDA MEMBER CONTACT Callington Haven \ Bob Middleton, Welding Product Manager \ 02 9898 2751 \ bmiddleton@callington.com \ callington.com 6 – Australian Stainless Issue 73
FOOD & BEVERAGE
Bankwest Stadium
Stainless feeds the spectator appetite Stainless steel continues to be the material of choice for commercial kitchen equipment, meeting and exceeding the rigorous demands of busy food service operations. Dubbed as the ‘Home of Sport in Western Sydney’, Bankwest Stadium opened in April 2019 in the heart of Parramatta. The 30,000-capacity, multi-purpose rectangular stadium features a steep tiered seating arrangement across five levels, offering the best viewing quality of live events. Sport matches including rugby league, rugby union and soccer are some of the arena’s main events. To complement the unparalleled live event experience, the stadium’s clever design ensures spectators are never more than 30 metres away from onsite food outlets and amenities. The stadium features 16 food and beverage outlets, 11 kitchens and five bars. ASSDA Member and Accredited Fabricator Stoddart delivered a bespoke solution for the 32 food and beverage areas with the fabrication, supply and installation of an extensive range of stainless steel commercial kitchen and food service equipment. The major kitchen fit outs by Stoddart included the supply of Halton ventilation exhaust hoods manufactured under license at their Karawatha site in Brisbane. Food service equipment supplied included commercial combi-steamer ovens, Adande refrigerated drawer systems and Anets deep fryers, brands exclusively imported and distributed by Stoddart in Australia. Stoddart’s own Culinaire range of commercial kitchen equipment was custom fabricated, manufactured, supplied and installed. This included vertical and standard hot cupboards, bain-maries, hot food slides and cold food displays. In addition, wash basins, work benches, counters, shelves, wall sheeting and spine walls were also manufactured and supplied. TIG welding techniques were used across the different goods and services provided. As an ASSDA Accredited Fabricator,
Stoddart’s strong expertise in stainless steel design and fabrication ensured the strict requirements of food equipment manufacture were met. Correct surface finish, avoiding cross-contamination of materials, and hygiene and cleanability of stainless steel food equipment are some important considerations in delivering quality products expected to perform in busy food operations. Overall, a significant amount of 304 grade stainless steel was used for the project, including 8,500m2 of coil, 3,987 linear metres of tube, 158 flat sheets (1.2mm thick, 914mm and 1219mm wide sheets in various lengths) and perforated sheets (1.2mm thick, 500mm wide in various lengths). Stainless steel coil and tube was supplied by ASSDA Member Dalsteel Metals, while the stainless steel sheet was supplied by ASSDA Member Midway Metals. Stainless steel is a versatile and attractive material offering corrosion and heat resistant properties. It has a non-porous surface, therefore it is less reactive and does not affect the taste of food. Commercial kitchens are the busiest places in the hospitality industry, and stainless steels meet the high-level standard for delivering excellent hygiene, cleanliness and durable equipment. In addition, stainless steel delivers a long service life of over 10 years for food service equipment and over 20 years for fabricated goods including exhaust hoods, benching and wall sheeting. Bankwest Stadium is now a distinctive landmark for Western Sydney, and with the use of stainless steel, offers an exciting range of food options highlighting the flavours of local operators.
Copyright: Stoddart
ASSDA MEMBER CONTACT Dalsteel Metals \ Les Anderson, Service Centre Manager \ 07 3216 2575 les.anderson@dalsteel.com.au \ dalsteel.com.au Midway Metals \ Craig Wallace, Brisbane Manager \ 07 3382 9500 craigw@midwaymetals.com.au \ midwaymetals.com.au Stoddart \ Matthew Roe, Marketing Executive 07 3440 7470 \ mroe@stoddart.com.au stoddart.com.au 7 – Australian Stainless Issue 73
ASSDA Stainless Steel
Stock Guide ASSDA is excited to present the sixth edition (2021) of the Stainless Steel Stock Guide, a free resource aimed at disseminating an up-to-date breakdown of 'ex-stock' stainless steel materials on offer in Australia. It is an online-only publication detailing the stocking portfolio of commonly used stainless steel semi-finished and finished materials. Contents include: • Sheet, Coil and Plate
• Mesh
• Safety Flooring Products
• Pipe and Tube
• Bar
• Pipe and Tube Fittings
• Wire and Wire Rope
• Fasteners
STAST INL AIESS N LE SS STEST ELEE STO IDE L STCK O CGU KG 2021 U ID E
EDITIOEDIT N 6 –ION AUGU 6 – ST 2021 AUG UST
Who is it for?
Anyone who needs or wants to know what stainless steel materials are readily available, and in what form or specification.
Ess Essen tialent inform ial info ation for anyon rmation e one designing in stainless for any A gen A gener steel. des ing in ic eric stocksto list ckoflistprodu cts stainless ste reportedign of pro to be regul duc ts reporte arly availael. ble ex-stock. d to be reg ularly availab le ex-stock.
As a designer, specifier or engineer, use the Stainless Steel Stock Guide to better understand the relevant specification, sizes and product dimensions of readily available materials to aid project management and delivery. As a fabricator or manufacturer of stainless bearing goods, use it not only for your day-to-day procurement queries, but to also find ways to streamline operations, better manage inventories and optimise your own production processes.
Available for FREE download at www.assda.asn.au
PLATINUM MEMBERS:
GOLD MEMBERS:
SILVER MEMBERS:
Stanch Stainless Steel Co., Ltd.
Acerinox \ Amity Pacific \ Aqseptence Group \ Arcus Wire Group \ AusPress MEI \ Austral Wright Metals \ Australian Stainless Distributors \ Callidus Welding Solutions \ Ching-Hann Industries Co., Ltd. \ Dalsteel Metals \ Fagersta Steels \ Metal Centre Australia \ Prochem Pipeline Products \ Sanwa \ SIJ Metal Ravne \ Stainless Steel Wire & Mesh \ Vulcan Stainless \ Yue-Seng Industrial Co., Ltd.
Stoddart YC Inox Co., Ltd.
AUSTRALIAN STAINLESS MAGAZINE MORE INFO: Enquiries or further information on any material presented in this publication should be directed to ASSDA: Level 6, 200 Adelaide St, Brisbane Qld 4000 \ +61 7 3220 0722 \ assda@assda.asn.au \ assda.asn.au EDITORIAL: Contributions of story ideas specialising in stainless steel and its applications are welcome from Members of ASSDA. ADVERTISING: Advertise in the only publication that reaches are targeted group of 5000+ in the Australian stainless steel industry. Rates available at www.assda.asn.au. CONTACT: Lissel Pilcher, Editor: lissel@assda.asn.au DISCLAIMER: ASSDA sources articles and advertisements from a variety of contributors and accordingly does not accept responsibility for the accuracy of the contents of this publication nor the suitability of specific applications referred to herein for any particular use. Competent advice should be sought before acting on any matter contained in this publication.