IF VALVE FAILS TO OPEN: Check for leaks
in line from unloader or pressure release valve to automatic drain
valve. Check to see that timer has not been unscrewed too far. If
trouble persists, remove intake plug and clean chamber. If this
fails, remove diaphragm cover and check the diaphragm and diaphragm
plate for cause of non-operation.
IF VALVE FAILS TO CLOSE: Check timer
adjustment to see that air is bleeding out. If air continuously
bleeds from timer while compressor is running, centrifugal unloader
or pressure switch release valve is leaking. Check compressor or
pressure switch literature/instructions for remedy. If air
continuously bleeds from timer when compressor is not running,
inspect the compressor check valve. Replace and/or clean check
valve if air is leaking back from tank.
If timer works correctly and valve fails to close, remove intake
plug, spring and valve stem assembly. This assembly includes the
valve stem, o-ring, disc and nut. They are not attached to the
diaphragm plate and will drop out through the bottom of valve
chamber opening. Clean intake chamber and disc and replcae if disc
is scored. If valve opens and only air is exhausted, check flexible
tube in tank. It must reach the bottom of the tank and be free of
leaks. Timer may be adjusted under operating conditions.
Shut off and lock out/tag out compressor. Drain tank completely
of air and water before installing or servicing valve. Failure to
relieve pressure may cause injury and/or equipment damage.
Disconnect auto drain from receiver at the bottom fitting. Remove
intake plug and clean screen which may become clogged with scale or
debris from tank. Unless the fitting and screen are kept clean,
debris may work into the drain valve seat, causing the valve to
stick or fail to close.