Minimum Pressure Valve Maintenance; Blowdown Valve Maintenance; Solenoid Valve Maintenance; Pressure Regulator Maintenance - Sullair ShopTek ST18 Operation & Maintenance Manual

ST18 & ST22 (U.S.A. & Mexico) Operation & Maintenance Manual
6.4.7 Minimum pressure valve
maintenance
1. Valve body
2. Check valve assembly
3. Allen fixing screw
4. Anti-loose washer
5. Washer
6. Check valve spring
7. Piston components
Minimum pressure valve repair kit part number: 88291011-688
Figure 6-5: Minimum pressure valve
1. Shut down the compressor and bleed pres-
sure to zero.
2. Disconnect the pipe connected to the mini-
mum pressure valve and remove the valve
from the cover of the fluid/air separator.
8. O-ring
9. Piston assembly
10. Positioning ring
11. Spring
12. Piston guide pole
13. Top cap
14. Inner hex screw
88291013-137 R05
Subject to EAR, ECCN EAR99 and related export control restrictions.
3. Unscrew the top cap of the valve and
remove the piston assembly from the valve.
4. Clean the valve and piston assembly care-
fully.
5. Replace the O-ring, applying a layer of
grease to the O-ring and the piston.
6. Apply Loctite gasket maker to the top cap of
the valve and reassemble the valve.
7. Reinstall the valve on the cover of the fluid/
air separator tank and reconnect the pipe.
6.4.8

Blowdown valve maintenance

Maintenance of the blowdown valve is primarily about
replacing the O-ring (repair kit part number 88291008-
365).
1. Shut down the compressor and bleed pres-
sure to zero.
2. Screw off the bolts and remove the top cap
of the blowdown valve.
3. Remove the spring, piston, O-ring, etc.
4. Replace washer and all O-rings.
5. Reassemble the blowdown valve.
6.4.9

Solenoid valve maintenance

The solenoid valve needs little service. However, if the
solenoid is reacting slowly or is leaking and the working
voltage is correct, you should clean the valve or, if neces-
sary, replace it (repair kit part number 88290021-950).

6.4.10 Pressure regulator maintenance

1. Shut down the compressor and bleed pres-
sure to zero.
2. Unscrew the locking nut and turn the adjust-
ing screw counterclockwise until the spring is
relaxed. Now the adjusting screw is not
under pressure.
3. Unscrew the spring chamber and take out
the spring seat, upper assembly, and gasket.
4. Unscrew the valve plate nut and remove the
valve plate, membrane, and retainer ring.
5. Replace the retainer ring with a new retainer
ring.
6. Reassemble the retainer ring, membrane,
and valve plate and tighten the valve plate
nut.
7. Replace the gasket with a new gasket.
8. Check the condition of the spring and if it is
damaged, replace it with a new spring.
6: Maintenance
33