Flowserve Valtek VL-ES Actuators - Manual (Page 6)

Valtek VL-ES Actuators FCD VLENIM0114-00 – 09/06
6
3.5 Clean any dirt or foreign material from the actuator and piston stems.
3.6 If an air filter is supplied, isolate the air filter, then check and replace the cartridge as necessary.
4 Dissassembly of VL-ES Actuator
To disassemble the VL-ES actuator, refer to Figure 1 and 2 and then proceed as follows:
4.1 Shut off the air supply. If the actuator is installed on a Flowserve valve, remove the valve using the
appropriate Installation Operation and Maintenance instructions.
WARNING: To avoid serious injury, depressurize the line to atmospheric pressure and drain all fluids
before working on the actuator.
4.2 Disconnect all tubing.
4.3 Remove the actuator from the valve body using air in the cylinder to move the plug stem to approxi-
mately mid stroke position. Remove the stem clamp and release the air from the cylinder slowly.
Remove the yoke bolts. Using lifting rings in the place of two of the top plate bolts, lift the actuator
up off the valve body subassembly. Set the actuator on a workbench or other sturdy work surface.
WARNING: When lifting an actuator with lifting straps through the yoke legs, be aware that the
center of gravity may be above the lifting point. Therefore, support must be given to prevent the
actuator from rotating, causing serious injury to personnel or damage to nearby equipment.
WARNING: Removing the stem clamp without relieving the pressure between the plug stem and the
actuator stem can cause the stem clamp to suddenly jump, causing serious injury to personnel or
damage to nearby equipment.
4.4 Remove the cover plate bolts, cover plate and cover plate O-ring.
4.5 For fail open, air to close (ATC) actuators, apply air the bottom port on the actuator, moving the
piston to the top of the cylinder. Remove the piston stem half rings, collar and thrust washer.
4.6 Remove all but two of the spring-can bolts. Leave in two bolts on opposite sides of the actuator.
Remove the two remaining bolts one flat at a time, turning each in order. Remove the spring-can
by lifting it clear of the actuator.
DANGER: The spring-can contains a pre-tensioned spring. The spring-can must not be disas-
sembled in the field and requires special equipment and training to service. Disassembling the
spring-can will cause serious injury or death. For instructions on decommissioning the spring-can,
see section 7.0 below.
4.7 For fail closed, air to open (ATO) actuators, remove the spring guide and thrust washer.
4.8 Remove the four self-locking tie rod nuts by unscrewing them in an alternating pattern. Remove
the cylinder end cap.
NOTE: When removing the tie rods, spinning the self-locking nuts may cause the entire rod to turn,
removing the rods instead of the nuts. In this case, do not use vise-grip pliers or a similar device to keep
the rod from turning. This will damage the surface of the tie rod and can cause the rod to fail in service.
Instead allow the rod and nut to come out as one. Once the rod and nut are clear, use a soft grip vise to
turn the nut off the tie-rod.
4.9 If the tie-rods did not come out with the locknuts, remove the tie rods from the yoke using two
nuts locked together on the upper threads.
c
c
c
b