Manitou Helical Hydraulic Rotary Actuators L20 Series Repair Manual 647187 - PDF DOWNLOAD

647187EN (03/09/2012)

ROTARY ACTUATORS HELICAL HYDRAULIC L20 SERIES Repair manual

MANITOU BF B.P 10249 - 44158 ANCENIS Cedex Tél. 33 (0) 2 40 09 10 11 Fax commercial France : 02 40 09 10 96 // Export : 33 2 40 09 10 97 www.manitou.com

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1st Date of Issue : 03 / 09 / 2012

647187EN

DATE OF ISSUE 03 / 09 / 2012

OBSERVATION - 11ststISSUE PUBLICATION (HF L20SM/04.12)

THE TEXTS AND PICTURES IN THIS DOCUMENT CANNOT BE REPRODUCED EITHER TOTALLY OR PARTLY.

INTRODUCTION Contents Introduction Contents …........................................................................................................................................................................................................ 2 Introduction to the product........................................................................................................................................................................... 3 General safety regulations ……................................................................................................................................................................... 3 Product identification ………....................................................................................................................................................................... 4 Operating principle …………....................................................................................................................................................................... 5

Tools Tools required ..................................................................................................................................................................................................... 6

Drawings Spare parts............................................................................................................................................................................................................ 7 Assembly drawing............................................................................................................................................................................................. 8 Exploded views................................................................................................................................................................................................... 9 Parts list …………........................................................................................................................................................................................... 10

Dismantling Before dismantling ......................................................................................................................................................................................... 11 Dismantling....................................................................................................................................................................................................... 11 Inspection.......................................................................................................................................................................................................... 16

Assembly Assembly ........................................................................................................................................................................................................... 17

After assembly Lubricating the thrust washers .................................................................................................................................................................. 21 Testing the actuator ....................................................................................................................................................................................... 22 Installation and bleeding ............................................................................................................................................................................. 23 Troubleshooting guide.................................................................................................................................................................................. 24 Warranty...............................................................................................................................................................................................................25

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INTRODUCTION Introduction to the product

For more than 40 years, the Helac Corporation has been renowned for its innovative designs of rotary hydraulic actuators and accessories for construction equipment. Helac products are known for their high output torque, their compact build, their exceptional load capacities and their sturdy, reliable performance.

Helac’s L20 Series rotary actuators are used to swivel work platforms on self-propelled lifting equipment, where they have become the industry standard.

The L20 Series is available in different sizes and various assembly designs (see page 4 for additional details).

Over 1000 manufacturers of mobile industrial, construction and mining plant worldwide place their trust in Helac actuators to perform functions such as rotation, positioning, manipulation, vehicle turning and indexing.

General safety regulations

SPECIAL PRECAUTIONS To avoid physical injury and damage to the equipment: Read the installation, maintenance and repair procedures in the Repairs and Maintenance Manual.

WARNING Fluid projections: Contents under high pressure.

Wear approved eye protection.

Be careful when removing plugs and connections.

WARNING To avoid injury and damage to the product: Hold the product down firmly on a grooved work platform or in a vice.

ADVICE To avoid contaminating the wear parts: Be careful to work in a clean environment.

In many uses of L20 actuators, there are several points where fingers or other items could possibly become trapped and severe injury inflicted. Extreme care must therefore be exercised and you must keep away from any rotating part while the hydraulic system is being bled and the equipment is in use.

After reconditioning or repairing an actuator, you must bleed the air from the actuator and the machine’s hydraulic system. See page 25 for instructions on bleeding the system.

Pay careful attention while bleeding the actuator; keep your hands, fingers and any other part of your body well away from any rotating parts.

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INTRODUCTION Product identification Each Helac actuator has its own serial number.

This is comprised of five or six figures and must be provided before discussing any problem with parts or repairs.

The serial number is located on the Identification (ID) label affixed to each actuator. This label is in thin silvered plastic with a self-adhesive back.

The instructions are printed on it in black.

The label is located either on the actuator’s side plate or its casing tube. In certain instances, the ID label may be covered in paint by the original equipment manufacturer. The typical locations for sample labels are shown below.

Please note that the model number may start with HP or L20.

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The actuator’s serial number is also stamped on the side plate or the casing tube. It may be necessary to remove the paint to reveal the serial number.

If the ID label is not attached to the actuator or the stamped-on serial number cannot be found, the actuator’s basic model can be determined by measuring the external diameter of the flange’s tapped and drilled shaft.

Model

Flange diameter

L20-4.5

104.14 mm (4,10 po)

L20-8.2

116.84 mm (4,60 po)

L20-15

142.24 mm (5,60 po)

L20-25

170.18 mm (6,70 po)

L20-30

182.88 mm (7,20 po)

L20-39

195.58 mm (7,70 po)

INTRODUCTION Operating principle The L20 Series rotary actuator is a simple mechanism that uses Helac’s sliding channel technology to convert the piston’s linear motion into powerful shaft rotation. As shown in the illustration below left, each actuator consists of a casing with an integral grooved crown (1) and only two moving parts: the central shaft (2) and the ring piston sleeve (3). Please note that the L20 actuator’s shaft is fitted with an integral mounting flange and a bearing, which are not shown in the illustration.

The teeth in the spiral grooves machined onto the shaft engage with the corresponding grooves on the piston’s internal diameter. The piston’s external diameter has a second set of grooves, with reverse pitch, which engage with the corresponding grooves in the casing’s crown.

As hydraulic pressure is applied, the piston moves proportionally in the axial direction in the casing, in similar fashion to the operation of a hydraulic cylinder, while simultaneously the grooves drive the shaft’s rotation.

When the control valve is closed, the oil is sealed inside the casing, preventing the piston from moving and locking the shaft firmly in position.

The shaft is supported radially by the large upper and the lower radial bearings (see the drawings on pages 8 and 9). In the axial direction, the shaft is separated from the casing by upper and lower end stop washers.

The cap is adjusted for axial play and locked in position with locking screws or pins.

The L20 Series comes in various sizes.

All the actuators in the L20 Series have the same nominal internal diameter and the same basic elements, although the overall configuration of the parts may vary slightly depending on the model’s function.

Several L20 actuators are factory-fitted with balancing valves with four main functions: • To protect the actuator in the event of an overload • To enable the actuator to hold a given position without drifting when an external load is applied • To reduce hydraulic rebound by pressurising the hydraulic fluid • To provide a controlled stable rotation rate under off-centred load conditions.

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Bars indicate the starting positions for the piston and the shaft. Arrows indicate the direction in which they rotate.

The casing, together with its integral grooved crown, remains stationary. For the purposes of clarity, the shaft clamp, the bearings and the caps are not marked.

Application of fluid under pressure moves the piston in an axial direction, while the spiral grooves simultaneously turn the piston and the shaft. The double-spiral design increases rotation: the shaft rotates at approximately twice the piston’s rate.

Application of pressure to the opposite orifice returns the piston and the shaft to their initial positions.

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INTRODUCTION Tools required

Several basic tools are required for dismantling or assembling the actuator. The tools and their functions are described below.

1. PIPE VICE 2. HEXAGONAL WRENCH For removing and replacing the sealing plugs and locking screws.

3. VARIOUS SCREWS

13. SET OF HEX WRENCHES For removing and replacing the sealing plugs and locking screws (106, 110).

14. SEAL TOOLS For removing and installing seals and wear guides. Instructions for producing a seal tool are provided below.

15. PUNCH 16. POSITIONING PINS For removing and installing the cap.

4. SAFETY GOGGLES 5. CAP REMOVAL TOOLS (supplied with the Helac seals kit).

6. DRILL 7. ELECTRIC TORCH To assist in finding and examining the sync markings, any faults on the parts and the general condition.

8. RUBBER MALLET For removing and installing the piston and shaft sleeve assembly.

PRODUCTION OF A SEAL TOOL The seal tool is simply a screwdriver with a modified blade.

1. Heat the flat end with a blow torch until it is cherry red.

2. Place the heated end in a vice and fold the heated end over slightly.

3. Round off all the sharp edges on the heated part to a fine finish. The tool can be modified slightly to suit personal preferences.

9. PLASTIC CHUCK 10. LEVER For removing the cap and manually rotating the shaft.

11. FELT TIP MARKER To highlight the sync markings and mark out problem areas. A permanent ink marker is recommended.

12. T-HANDLED SCREW EXTRACTOR

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WARNING To prevent injuries: Take care using the screwdriver when it is hot.

INTRODUCTION Spare parts Spare parts must be ordered from the vehicle or equipment’s original manufacturer. Seals and bearings are only available in complete kits! In order to obtain the correct parts, you must provide the serial number of the actuator to be repaired. See “Product identification” on page 4. To identify the replacement parts required, check the assembly drawing on page 8 and the parts list on page 10.

Technical assistance Technical assistance is available from Helac Corporation, Monday to Friday, 07:00 to 16:00 US Pacific time, by calling 800-327-2589. Please have the actuator’s serial number to hand (the serial number is stamped on the actuator’s casing: see page 4).

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DRAWINGS Assembly drawing Typical L20 Series actuator The configuration of the shackles and/or the output shaft flanges may be different.

OPTIONAL BALANCING VALVE COLLECTOR, REFERENCE No. 401 MOVEMENT CONTROL, REFERENCE No. 403

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DRAWINGS Exploded views

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PARTS LIST Parts list

PARTS

SEALS

REFERENCE

DESCRIPTION

QUANTITY

1 2 3 4

CASING SHAFT PISTON SLEEVE CAP

1 1 1 1

HARDWARE DESCRIPTION

103.1

SCREW (OPTIONAL) WASHER (OPTIONAL) SEALING PLUG SEALING PLUG STOP PIN LOCKING SCREW

106.1 106.2 109 113

DESCRIPTION

200 202 204 205 207 304.1

T JOINTS T JOINTS O-RING CUP SEAL THRUST RING EXCLUSION JOINT

QUANTITY 1

REFERENCE

DESCRIPTION

302 304

WEAR GUIDE END STOP WASHER

1 1 1 2 6

1 1 1 2 1 2

HYDRAULIC FLUID: ISO-VG-46

QUANTITY 2 2

ACCESSORIES REFERENCE

DESCRIPTION

400

STOP PIPE (OPTIONAL) BALANCING VALVE MOVEMENT CONTROL VALVE

401 403

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QUANTITY

BEARINGS

REFERENCE

103.2

REFERENCE

QUANTITY 1 1 1

DISMANTLING Before dismantling Before dismantling

ADVICE

All the numbers between the brackets refer to parts in the parts list on page 10.

Before dismantling, check whether the actuator shows any sign of corrosion. Significant corrosion can create difficulties in removing the locking screws (109) and unscrewing the cap (04). If there is any corrosion, soak the stop pins and the cap in penetrating oil for several hours before dismantling.

The dismantling operation is made considerably easier if the actuator is firmly held on the bench.

A pipe vice or mounting jig is very useful.

Dismantling SPECIAL PRECAUTIONS To avoid physical injury and damage to the equipment: Read the installation, maintenance and repair procedures in the Repairs and Maintenance Manual.

WARNING To avoid injury and damage to the product: Hold the product down firmly on a grooved work platform or in a vice.

WARNING Fluid projections: Contents under high pressure.

Wear approved eye protection.

Be careful when removing plugs and connections.

ADVICE To avoid contaminating the wear parts: Be careful to work in a clean environment.

1. Remove the sealing plugs (106.1) (106.2) and drain the oil. Inspect the oil for any signs of contamination such as water or metal shavings.

2. Remove the assembly screws (113) covering the cap’s stop pins (109).

3. Drill a hole in the centre of each stop pin with a 3mm (1/8”) drill bit to a depth of around 5mm (3/16”).

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DISMANTLING Dismantling 4. Remove the stop pins with a screw extraction tool such as an “Easy Out” (a size 2 is illustrated).

7. Remove the cap (4) and put it carefully on one side for later inspection.

If you cannot remove the pin with the screw extractor, use a 5/16” (8mm) drill bit to drill out the whole pin. Take care not to drill down more than 12.5mm (1/2”).

8. Remove the stop tube (400) if the actuator is fitted with one. The stop tube is available as an option and restricts the actuator’s rotation.

5. Install the cap removal tools supplied in the Helac seals kit (1/4-20).

6. Using a metal bar or similar tool, unscrew the cap (4) by turning it in the counterclockwise direction.

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DISMANTLING Dismantling 9. Each actuator has 2 sets of small sync markings stamped on it, indicating the synchronisation points for the sets of grooves.

These markings may vary slightly in position and appearance from one model to another. One set indicates the synchronisation point between the piston sleeve (3) and the casing (1) (left-hand photo), the other set between the piston and the shaft (lower photo). To ensure that the end stop rotates correctly and is positioned precisely, the actuator must be correctly synchronised when it is refitted. The stamped sync markings can be used as they are but it is simpler to highlight them with a marker pen before dismantling, as shown in the steps below.

11. Remove the shaft (2) by turning it in the counter-clockwise direction. As the shaft turns, it gradually disengages from the piston sleeve (3) and can then be removed. It may be necessary to tap the threaded end of the shaft with a rubber mallet.

12. As in step 9 above, before removing the piston (3) make a mark on the casing’s crown (1) with respect to the external grooves on the piston. The casing’s crown (1), the piston and the shaft (2) should now all have a sync mark.

10. Before removing the shaft (2), clearly highlight the sync point clearly between the shaft and the piston sleeve (3) with a felt tip marker. This greatly simplifies synchronisation when refitting the actuator.

13. To remove the piston (3) use a rubber mallet and a plastic chuck to avoid damaging the piston and the casing’s bore.

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DISMANTLING Dismantling 14. At the point where the piston’s grooves disengage from the teeth of the casing’s grooves, mark the piston and the casing with a marker pen as shown.

17. Remove the main pressure seal (205).

18. Remove the end stop washers (304) from the cap (4) and the shaft (2).

15. Remove the O-ring (204) and the thrust ring (207) from the cap (4).

ADVICE To avoid damaging the machined parts: Carefully remove the seals using removal tools with rounded edges.

16. Remove the wear guide (302) from the cap (4) and the shaft (2).

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19. Remove the O-ring (304.1) from its groove in the cap (4) and the shaft (2).

DISMANTLING Dismantling 20. Remove the seal (202) from the piston’s external diameter.

21. Remove the seal from the piston’s internal diameter (200).

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ASSEMBLY Inspection

ADVICE

Before assembling the actuator, the steps in this procedure must be scrupulously followed to ensure that the actuator works properly.

1. Clean all the parts in a solvent bath and dry them with compressed air before inspecting them.

2. Carefully check that all the critical areas have no defects in their surface finish: seal housings, bearing housings, thrust surfaces, the shaft surface, the casing’s bore and the groove teeth.

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ADVICE

Small surface or minor scratches can be carefully polished away.

ASSEMBLY Assembly SPECIAL PRECAUTIONS To avoid physical injury and damage to the equipment: Read the installation, maintenance and repair procedures in the Repairs and Maintenance Manual.

2. Coat the thrust washers (304) generously with lithium grease. Fit the thrust washer (304) on the shaft (2) and the cap (4).

WARNING To avoid injury and damage to the product: Hold the product down firmly on a grooved work platform or in a vice.

WARNING Fluid projections: Contents under high pressure.

Wear approved eye protection.

Be careful when removing plugs and connections.

3. Install the exclusion joint (304.1) in the appropriate housings in the shaft (2) and the cap (4) around the external edge of the thrust washer (304).

ADVICE To avoid contaminating the wear parts: Be careful to work in a clean environment.

1. Before reassembly, gather all the parts and tools together in one place. Use the cutaway drawing as a reference for orienting the seals.

4. Fit the main pressure seal (205) on the shaft (2) and the cap (4) using a seal fitting tool (see “Tools required” on page 6). Use the tool for seals with a circular movement.

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ASSEMBLY Assembly 5. Fit the wear guide (302) on the cap (4) and the shaft (2).

Starting with the internal seal (300), fit one end of the thrust ring in the internal housing and then insert the rest with a circular movement. Check that the bevelled ends overlap correctly.

Fit the other thrust ring in the upper housing.

Repeat both these steps for the external seal (202).

6. Fit the O-ring (204) and the thrust ring (207) in the housing for the cap’s internal seal (4).

8. Insert the piston (3) in the casing (1), as shown, until the piston’s external seal (202) is in contact with the interior bore of the casing.

7. Fit the internal T seal (200) in the appropriate housing on the piston (3). Use a circular movement to ensure that the seal is correctly fitted in the housing.

Fit the external T seal (202) stretching it around the housing with a circular movement.

Each T seal has 2 thrust rings (see the orientation on the assembly drawing on page 8).

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ASSEMBLY Assembly 9. Looking down the casing’s bore from the end of the shaft flange, turn the piston (3) until the markings made on the piston and the casing (1) during dismantling are aligned as shown. With a rubber mallet insert the piston into the casing until the teeth in the grooves are in contact.

10. Looking down the bore from the opposite end of the casing (1), check that the sync markings are aligned correctly. Turn the piston as necessary until it is aligned and then gently insert the piston (3) in the casing until the grooves are engaged. Insert the piston into the casing until it comes in contact with the grooved crown.

11. Insert the shaft tube (2) in the piston (3).

Take care not to damage the piston’s seals.

Do not engage the teeth of the piston’s grooves at this time.

12. Looking at the actuator from the end opposite the shaft flange, use the existing sync markings to align the teeth of the shaft’s grooves (2) to the teeth of the piston’s internal grooves (3). When the markings are aligned, tap the end of the shaft flange gently with a rubber mallet until the teeth are engaged.

13. Fit 2 bolts in the flange’s threaded holes.

With a metal bar, turn the shaft in the clockwise direction until the wear guides rest of the inside bore of the casing.

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ASSEMBLY Assembly ADVICE

When the shaft is turning, take care not to disengage the piston and casing grooves.

14. Fit the stop tube (400) on the end of the shaft if necessary. The stop tubes are available as an option to restrict the actuator’s rotation.

15. Coat the threads on the end of the shaft with anti-grip grease to avoid scuffing.

16. Screw the cap (4) on to the shaft (2). Check that the wear guide remains in place on the cap while it is being screwed into the casing (1).

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17. Tighten the cap (4) with a metal bar. In most cases, the initial holes for the locking pins will be aligned.

18. Insert the locking pins (109) supplied in the Helac seals kit with the depression facing upwards. Then push the locking pins right down to the bottom of the hole with a punch.

19. Insert the locking screws (113) in the locking pins. Tighten to a torque of 2.8 Nm (25 in-lb).

ASSEMBLY Lubricating the thrust washers 1. After assembling the actuator but before putting it into service, the thrust washers must be coated with lithium grease.

There are 2 greasing holes on each side of the shaft flange and the cap. They are sealed with assembly screws (113) and locking screws. Remove the screws from these greasing holes (see the exploded drawing on page 9).

ADVICE

Insert the nozzle of a grease gun in one of the holes and apply grease to the shaft flange.

Continue to apply grease until it flows out of the opposite hole. Operate the actuator 5 times and then apply grease again.

Repeat this procedure with the cap. Insert the 2 assembly screws in the greasing holes and tighten to a torque of 2.8 Nm (25 in-lb).

If a hydraulic test bench is not available, the actuator can be turned by hand; to do this, open the pressure holes and use a lever with the assembly screws inserted into the shaft clamp and turn the shaft in the desired direction.

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AFTER ASSEMBLY Testing the actuator SPECIAL PRECAUTIONS To avoid physical injury and damage to the equipment: Read the installation, maintenance and repair procedures in the Repairs and Maintenance Manual.

WARNING To avoid injury and damage to the product: Hold the product down firmly on a grooved work platform or in a vice.

WARNING Fluid projections: Contents under high pressure.

Wear approved eye protection.

Be careful when removing plugs and connections.

ADVICE To avoid contaminating the wear parts: Be careful to work in a clean environment.

If a test bench is available, you should use it to test the actuator.

The separation pressure, the pressure at which the shaft starts to turn, should be approximately 28 bars (400 PSI). Operate the actuator at least 25 times at a pressure of 210 bars (3000 psi). After 25 rotations, increase the pressure to 315 bars (4500psi) to check whether there are any leaks or cracks. Repeat this test after rotating in the opposite direction.

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Detecting an internal leak in the actuator If the actuator is fitted with a balancing valve, plug the valve’s holes. Connect the hydraulic lines to the holes in the casing. Bleed the air from the actuator (see Installation and bleeding, page 25). Turn the shaft at 210 bars (3000 psi) up to the end of its rotation and maintain the pressure. Remove the hydraulic line from the unpressurised side.

A continuous flow of oil from the open hole in the casing indicates an internal leak in the piston. Refit the hydraulic line in place and turn the shaft to the end of its rotation in the opposite direction. Repeat the procedure indicated above for the other hole. If there is an internal leak, dismantle the actuator, inspect it and repair it.

AFTER ASSEMBLY Installation and bleeding SPECIAL PRECAUTIONS To avoid physical injury and damage to the equipment: Read the installation, maintenance and repair procedures in the Repairs and Maintenance Manual.

WARNING To avoid injury and damage to the product: Hold the product down firmly on a grooved work platform or in a vice.

1. Connect a transparent vinyl hose 5 x 8mm (3/16 x 5/16”) (internal/external diameter) 1.5m (5 feet) long to each of the bleed screws and hold it in place with hose clips.

Place the vinyl hoses in a clean 20-litre (5 gallons) can to collect the bleed oil. In some cases, the oil may be able to be returned to the reservoir when the procedure is complete.

TYPICAL CONFIGURATION OF AN ACTUATOR USED FOR ROTATING A WORK PLATFORM

WARNING Fluid projections: Contents under high pressure.

Wear approved eye protection.

Be careful when removing plugs and connections.

BLEED HOLES

ADVICE To avoid contaminating the wear parts: Be careful to work in a clean environment.

After installing the actuator on the equipment, it is important that the safety devices, such as the ties and safety cables, should have been reconnected correctly.

To bleed the air from the hydraulic lines, connect them together to create a closed loop and use them to pump the hydraulic fluid. Consult the original manufacturer’s operating manual or hydraulic system diagram to determine which hydraulic lines must be connected. The length and the diameter of the hydraulic supply lines and the pump’s capacity determine the pumping time required to bleed the hydraulic system.

Bleeding may be necessary if excessive rebound occurs after connecting the actuator to the hydraulic system. The original manufacturer does not specify all the actuators with bleed connections; please see their location on the drawing below. The procedure below is recommended when at least 8 litres (2 gallons) are being bled.

2. With an operator on the platform, open the two bleed nipples a quarter-turn. Turn the platform hydraulically up to the rotation end stop (in either direction, clockwise or counter-clockwise) and maintain the hydraulic pressure. Oil with tiny bubbles of air flows down the hoses. Bleed off at least 2 litres (0.5 gallon) of fluid from the actuator.

3. Keep the connections open and turn the platform in the opposite direction up to the end stop. Maintain the hydraulic pressure until an additional 2 litres (0.5 gallon) of fluid has been pumped into the receptacle.

4. Repeat steps 2 and 3. After bleeding off the last 2 litres (0.5 gallon), close both the bleed nipples before leaving the end stop position.

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TROUBLESHOOTING GUIDE Troubleshooting guide

PROBLEM

SEE CAUSES AND SOLUTIONS BELOW

The shaft turns slowly or not at all

1-6

The machine operates irregularly or does not respond

7

The shaft does not turn completely

8-9

The selected position cannot be maintained

3-4-7

CAUSE

SOLUTION

1. Insufficient output torque

Check the operating pressure. Do not exceed the original manufacturer’s recommended pressure. The load may be greater than the actuator’s maximum capacity.

2. Low fluid flow

Check whether the holes are blocked and that there are no restrictions or leaks in the hydraulic lines.

3. Internal leak in the control or balancing valve

Disconnect the hydraulic lines and the by-pass valve. Leave the holes open and operate the actuator via the holes in the casing (do not exceed the original manufacturer’s operating pressure). The valve must be replaced if there is a constant flow of fluid from the valve’s holes.

4. Leak from the shaft or piston seal

Remove the plug and the valve holes from the casing. Operate the actuator via the holes in the casing. Test for internal leaks as indicated in the Testing section on page 22 of this manual.

5. Corrosion accumulated on the thrust surfaces

Recondition the actuator. Remove all the rust and polish the surfaces.*

6. Blown seals and composite bearings caused by incompatible hydraulic fluid (standard actuators only)

Recondition the actuator. Use a fluid compatible with the seals and bearings.

Contact Helac for any additional information.

7. Air in the actuator

Bleed the air from the actuator. Consult the bleeding procedure, starting on page 23.

8. Deformed or chipped teeth on the grooves due to an overload

Check that the grooves are not jammed. It may not be possible to recondition the actuator: it may have to be replaced.

9. The connections for the holes create an obstruction while the piston is travelling

Check the length of the thread on these connections. The connections should not reach the inside of the casing’s bore during travel.

* Replacement parts may be required

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WARRANTY Warranty Warranty for the rotary hydraulic actuator Standard warranty Helac Corporation guarantees its products against any material or manufacturing faults. Helac Corporation will replace or repair any products that present faults under normal operation and return the repaired or replacement products to the purchaser, carriage paid. Any claims under this warranty will be satisfied only by repair or replacement of the defective equipment or its components. No cash or credit reimbursement will be made for defective materials, manufacturing or workmanship defects, or ancillary costs. The products covered by the warranty must be returned to Helac Corporation at 225 Batters by Avenue, Enumclaw, Washington 98022, USA, carriage paid by the purchaser, for inspection by Helac Corporation, which will determine any fault.

The warranty is for a period of 12 months from the date of dispatch from Helac Corporation’s factories and for uses approved by Helac Corporation. This warranty is null and void if a product has been repaired or modified by any person not authorised by Helac Corporation or has been subject to improper use, negligence, an accident or an overload. Under no circumstances may Helac Corporation be held responsible for any ancillary or indirect damage. Helac Corporation reserves the right to make design or construction modifications to all its products without incurring any obligation to apply the same changes or modifications to previously sold products.

This warranty replaces any preceding warranty, whether implicit or explicit, and no other company or person is authorised to represent, nor accept on behalf of Helac Corporation, any liability associated with this sale of Helac Corporation products other than as presented here.

Actuator return and debit policy Unless otherwise agreed in advance, all actuators must be dispatched to Helac Corporation, carriage paid, within seven days of receipt of an authorisation for return. Before any return, an authorisation form for return of equipment (RMA) must be obtained from an authorised representative of Helac Corporation. After receiving the RMA form, the customer must provide, where applicable, the reference number, serial number, failure date, description of the problem and the customer’s claim number if not the reference number. Any dispatch to Helac Corporation must include the duly completed RMA form.

After receipt of the actuator by Helac Corporation at its factory, it is inspected and an authorised representative supplies a written report.

This report lists the results of the inspection and indicates whether the claim has been accepted or not under the warranty. Actuators returned for credit may be subject to restocking costs on the part of Helac Corporation.

If Helac Corporation does not receive a response to this report within 30 calendar days, the actuator will be scrapped or returned and an invoice for the amount to be debited, including carriage costs, will be sent to the initiator of the claim.

Replacement part return and debit policy The return of replacement parts normally stocked by Helac Corporation must be subject to prior authorisation. This includes all the seals and bearings, as well as any manufactured components. The return of any specially ordered item will be authorised on a case by case basis. All returns must be dispatched to Helac Corporation, carriage paid, within seven days of receipt of an authorisation for return. Helac Corporation levies a minimum charge of 20% for the cost of restocking.

Before any return, an authorisation form for return of equipment (RMA) must be obtained from an authorised representative of Helac Corporation. After receiving the RMA form, the customer must provide, where applicable, the reference number, date of receipt, description of the problem and the customer’s claim number. Any dispatch to Helac Corporation must include the duly completed RMA form.

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Remarks

26

Remarks

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