Compressor Inlet Valve; Minimum Pressure Valve; Blowdown Valve; Blowdown Switch - Boss 210 DUS JD4045 Service And Maintenance Manual

5.11 Compressor Inlet Valve

The compressor inlet valve is a normally open air intake valve bolted to the compressor airend. When
the system is shut down, this valve also acts as a check valve that prevents the air/oil mixture within the
compressor airend from entering the inlet piping.

5.12 Minimum Pressure Valve

To ensure there is adequate pressure to produce proper oil flow throughout the system, a spring loaded,
normally closed minimum pressure valve is set to maintain at least 80 PSI in the separator tank.

5.13 Blowdown Valve

The blowdown valve is a shuttle valve that vents system pressure to atmosphere when the system is shut
down. This is done to prevent the high torque load that would be required to overcome the static
pressure. The blowdown valve is stamped with an "I" and a "P". The "I" side is connected to dry air
from the separator tank, and the "P" side is the pilot signal coming from the compressor inlet valve.

5.14 Blowdown Switch

The system is equipped with a blowdown switch. This switch will sense pressure in the pilot signal to
the blowdown valve. If the system contains pressure, the switch will prevent the machine from starting.
This will prevent premature damage to the drive coupling.

5.15 Discharge Pressure Regulator Valve

This valve, located downstream of the separator element, is used to set the desired discharge pressure.
This valve will send a pneumatic signal to the inlet valve to start closing when the pressure exceeds the
setpoint. This signal will also adjust the speed of the engine. This system has a maximum operating
pressure of 160 PSI.
Description of Components
Most air tools operating pressure range is between 90 and 125
PSI. Operating above the tools recommended pressures will
decrease the life of the tool. Strictly adhere to tool operating
pressures and torque standards set forth by the tool
manufacturer.
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01/31/2012