Gardner Denver EAQ99T, Operating And Service Manual

Page: 33 / 78

13-21-601 Page 32
Figure 4-3 – BLOWDOWN VALVE
Blowdown Valve (Figure 4-3 – BLOWDOWN VALVE) - This valve normally is used for control functions,
but also serves to relieve reservoir pressure following a shutdown. The blowdown valve is a two-way
solenoid valve which is piped into the oil reservoir outlet ahead of the minimum pressure valve. When the
solenoid is de-energized, the valve opens and the coolant system is blown down. When the solenoid is
energized, the valve closes to allow the coolant system to pressurize. A control air check valve is
provided to ensure that the inlet valve is closed during blowdown.
Oil Level Gauge (Figure 1-6, page 12) - This gauge is located on the oil reservoir and indicates the oil
level. See Section 5 for information on how to correctly read the gauge and proper lubrication.
Figure 4-4 – MINMUM DISCHARGE PRESSURE/CHECK VALVE
Minimum Discharge Pressure/Check Valve (Figure 4-4, page 32) - An internal spring-loaded minimum
pressure valve is used in the final discharge line to provide a positive pressure on the coolant system of
the compressor even if the air service valve is fully open to atmospheric pressure. This valve also
functions as a check valve to prevent back flow of air from the shop air line when the unit stops, unloads,
or is shut down.