SPX FLOW W63 - U-Cup, O-Ring and Bearing Replacement; 4 Air-To-Lower 3-Position Actuator

Maintenance Waukesha Cherry-Burrell Brand W60/W80 Valves
Page 42 95-03022 08/2018
U-cup, O-ring and Bearing Replacement:
4” Air-to-Lower 3-Position Actuator
1. Inspect the lower piston U-cup seal (Figure 39, item 8).
2. Remove the worn U-cup seal. Do not score or nick grooves in
the piston (item 10).
3. Coat the new U-cup seal with Dow Corning
®
#7 Silicone
Lubricant or equivalent.
4. Slightly stretch the lubricated seal to fit over the lower piston.
Install the lower seal first with "U" pointing down. Install the
upper seal with the "U" pointing up. U-cup seals flare slightly
at the outer edges when properly installed.
5. Inspect the stem o-ring seal (item 6).
6. Remove the worn o-ring seal. Do not score or nick grooves in
the piston.
7. Coat the new o-ring seal with Dow Corning
®
#7 Silicone
Lubricant or equivalent.
8. Slightly stretch the lubricated seal to fit over the lower piston.
9. Inspect and replace the PTFE guide bearing (item 5) on the
piston as needed.
10. Connect the piston and spring assembly to the stem (item 3)
with the bolt (item 16).
11. Assemble the piston and spring assembly to the yoke (item
12).
12. Inspect the upper piston U-cup seal (item 17).
13. Remove the worn U-cup seal. Do not score or nick grooves in
the piston (item 15).
14. Coat the new U-cup seal with Dow Corning
®
#7 Silicone
Lubricant or equivalent.
15. Slightly stretch the lubricated seal to fit over the upper piston.
Install the lower seal first with the "U" pointing down. Install
the upper seal with the "U" pointing up. U-cup seals flare
slightly at the outer edges when properly installed.
16. Inspect the upper stem o-ring seal (item 11).
17. Remove the worn o-ring seal. Do not score or nick grooves in
the cylinder top and upper piston.
18. Coat the new o-ring seal with Dow Corning
®
#7 Silicone
Lubricant or equivalent.
19. Install the lubricated seal in the upper piston and cylinder top.
20. Assemble the upper piston and stem (item 1) to the cylinder.
Secure them with a hex nut (item 21). Place the cylinder over
the yoke, and install cap screws (item 9) to secure it.
21. Adjust the mid-position by loosening the hex nut (item 21)
and turning the stem (item 1).
NOTE: If the stems were disassembled during this maintenance
procedure, clean, prime, and apply Loctite
®
2440 Thread Locker,
according to manufacturer’s specifications, to the upper (item 1)
and lower (item 3) stems. Torque the stems to 200 in/lbs.
Figure 39: 4" Air-to-Lower 3-Position
Actuator
VA100-179
1
21
11
15
16
7
13
6
12
3
5
9
10
8
17
4
18
19
6