Craftsman 921.166420 - Manual (Page 5)

Parts & Features
See figures below for reference
V_
Regulator
The air pressure coming from the air tank is
controlled by the regulator. To increase the pressure
turn the knob clockwise and to decrease the
pressure turn the knob counterclockwise.
Regulator Gauge
Indicates the outgoing air pressure to the tool and
is controlled by the regulator.
Air Intake Filter
Provides clean air to the pump and must
always be kept free of debris. Check on a
daily basis or before each use.
Tank Pressure Gauge
Indicates the reserve air
pressure in the tank.
V.
Pressure Switch
This controls the power to the motor and also
the cut-in/cut-out pressure settings. This
switch serves as the Auto-On/Off positions
for the unit.
Tank Safety Valve
Used to allow excess tank pressure to escape into
the atmosphere. This valve should only open when
the tank pressure is above the maximum rated
pressure.
Pressure Relief Valve
The pressure relief valve located on the side of the
pressure switch, is designed to automatically
release compressed air when the air compressor
reaches cut-out pressure. The released air should
only escape momentarily and the valve should
then close.
V.
Check Valve
When the pump is not in operation the valve
closes to retain air pressure inside the tank. An
internal component.