DeZURIK
Cylinder Actuator for Knife Gate Valves
February 2022
Page 7
D11040
Cartridge Rebuild
To repair a cylinder actuator with the rod seal and wiper damaged by outside contaminants on the piston rod
(C14) during the retracting stroke.
This cylinder is a pressure-containing vessel! Removing any parts while under pressure
could cause personal injury or equipment damage. Release the pressure from both ends of
the cylinder before attempting disassembly or repair.
See Figure 3. The Rod Seal (C15C) and Wiper (C15B) are installed in the Cartridge (C15), along with an O-
ring (C15D).
Disassembling the Cartridge
1. Shut off the air supply
2. Remove the Cylinder Cartridge (C15) by unscrewing it from the Cylinder Head (C16) with a spanner
wrench.
3. Once Cylinder Cartridge (C15) is threaded free from the Cylinder Head (C16), slide Cylinder Cartridge
(C15) all the way down the Piston Rod (C14) and off.
4. Remove the Wiper (C15B), Rod Seal (C15C) and O-ring (C15D) from the Cylinder Cartridge (C15A).
Reassembling the Cartridge
1. Clean the Cylinder Cartridge (C15) grooves and lubricate with Dow Corning Number 44 lubricant, or
Dow Corning Number 55 in cylinders for
–40°C to –50°C service.
2. Insert the Rod Seal (C15C) into its groove, making sure it lies flat in the groove. Insert the PTFE
backing rings as shown in Figure 3. NOTE: The backing rings are cut with a bevel; make sure the
beveled ends of the rings ends meet but do not overlap.
3. Insert Wiper (C15B) into its groove.
4. Place O-ring (C15D) into its outer groove.
5. Carefully slide assembled Cylinder Cartridge (C15), in proper orientation, onto Piston Rod (C14) and
screw Cylinder Cartridge (C15) into the Cylinder Head (C16).
6. Mount cylinder onto valve and perform cylinder stroke adjustment as needed.