Gardner Denver VS80A, Operating And Service Manual

Page: 69 / 88

13-18-609 Page 68
9-1
SECTION 9
MINIMUM PRESSURE/CHECK VALVE
MINIMUM PRESSURE/CHECK VALVE
- This device maintains minimum pressure within the air/oil
reservoir, thus insuring (cooling/lubricating) oil injection flow into the compressors. It also serves as a
check valve to prevent back flow of compressed air flow from the customer
’s piping or pipe network back
into the compressor package when the compressor is not active.
The valve does not require maintenance or (internal) adjustment. Refer to Part List 13-18-505 for spare
parts.
Before servicing the minimum pressure valve, always stop the unit, release air
pressure, lockout and tagout the power supply to the compressor package. Failure to
release pressure or properly disconnect the power may result in personal injury or
death.
NOTICE
Working spring within valve body is under tension. Failure to relieve spring tension
gradually may cause serious injury upon cap removal.
Minimum Pressure/Check Valve (MPV) Inspection:
1. Be sure the unit is completely off and that the oil sump is depressurized
– including pipe works
between MPV and (external) isolation valve.
2. Disconnect, lockout and tagout power supply to the compressor package.
3. Carefully and gradually unscrew the valve cap from the body
– this will also release tension from the
working spring within the valve. After cap removal, all internal parts can be retrieved
– note their
relative positions during disassembly to help the re-assembly process. See Figure 9-1, page 69.
4. Re-assemble in reverse order
.