DISASSEMBLY
If it is necessary to disassemble the actuator for maintenance, disassemble the actuator from the valve.
It is important to ensure that the actuator is not pressurized before disassembling any components.
Work carefully and check that port 2 and 4 are open. Disassemble any accessories or connections.
When disassembling the single-acting actuators, make sure that the actuator is in the fail-safe position
(springs released). All disassembled and unreplaced components should be thoroughly cleaned and
checked for wear before reassembly.
1. Disassembly of the cover
Disassemble the screws. Caution: When disassembling a single-acting drive, loosen the cover
screws alternately. If after 4-5 screw turns there is no noticeable relief on all screws, this may be
an indication of damaged spring assemblies. In this case, the disassembly should be aborted.
Further cover disassembly may result in serious injury to maintenance personnel. Return actuator
to supplier immediately. For single-acting actuators, remove spring assemblies, remove cover
gasket and replace if necessary.
2. Disassembly of the pistons
Clamp the housing in a vice or similar tool. Turn the shaft until the pistons are released. Caution:
Compressed air must not be used to remove the pistons from the housing (projectile effect).
Carefully remove piston seals using a screwdriver, remove piston guide jaws and piston guides.
Replace O-ring in case of replacement.
3. Disassembly of the shaft
Carefully remove snap ring with snap ring pliers, remove washer and thrust washer. Press the shaft
downwards with light pressure on the upper side until it is possible to remove the cam and the
internal thrust washer. Then pull the shaft completely out of the housing. If the shaft cannot be
removed by hand, it can be driven out by lightly tapping the top of the shaft with a plastic hammer.
Remove the upper and lower piston bearings, and upper and lower seal rings. Replace the bearings,
internal and external thrust washers, and O-rings and, if necessary, replace all spare parts.
ASSEMBLY
Before assembly, all components must be clean and in perfect condition.
4. Mounting of the shaft
Install upper and lower shaft bearings, then install upper and lower shaft seals on the shaft. Grease
the outside of the shaft surface at the top and bottom. Partially insert the shaft into the housing,
then mount the cam in the desired position in relation to the position of the shaft head and shaft
flow and the direction of rotation of the drive. Then mount thrust washer, insert shaft completely.
Mount external thrust washer, mount washer and snap ring with snap ring pliers.
