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Product Manual

ManualsBrandsFS-Curtis ManualsStationaryML7.5 7.5-HP / 15-HP 120-Gallon UltraPack Pressure Lubricated Two-Stage Duplex Masterline Air Compressor (200/208V 3-Phase)
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MASTERLINE SERIES CAP200
Page 38 of 46 REV H JUNE 2017
INSTRUCTIONS
UNLOADER PILOT VALVE
FUNCTION
VV1002 Pilot Valve senses receiver (tank) pressure
when the receiver pressure rises to the preset “unload”
valve setting, the ball opens passing high pressure air
to the compressor unloading device. When the
receiver pressure drops to the preset “load” valve
setting, the ball closes venting the compressor-
unloading device to atmosphere. A manual override
permits manual unloading of the compressor when
placed in the up position.
INSTALLATION
Receiver (tank) pressure is connected to the 1/4” pipe
thread inlet. The compressor-unloading device is
connected to the 1/8” pipe outlet.
.
Fig. (17) Pilot Valve
ADJUSTMENT
PRESSURE ADJUSTMENT – The pilot valve is preset at assembly to a specified cutout and
differential. A limited adjustment of the unload pressure may be made in the field. To adjust
the unload pressure, unlock the locking nut (B), and turn the adjusting nut (A) clockwise for
higher pressures and counterclockwise for lower pressures.
CAUTION – As unload pressure is increased, the pressure differential between load and
unload pressure will become larger. As unload pressure is decreased, the pressure differential
will become smaller. A 30 PSI change in unload pressure will change the differential
approximately 10 PSI. Therefore large changes in pressure adjustment must not be mad
without adjusting the differential. A minimum differential of 10 PSI should be maintained to
prevent system from loading and unloading too frequently.
DIFFERENTIAL ADJUSTMENT – To increase the differential, unlock locknut (D), then turn
cap nut (C) very slightly clockwise – not more than 1/4 of a turn at time. To decrease the
differential, repeat above, but instead turn cap nut (C) counterclockwise. It may be necessary
at this point to fine adjust the unload pressure as outlined in the Pressure Adjustment by
turning the adjusting nut (A) in the proper direction.
MAINTENANCE – If the pilot valve becomes erratic or fails to operate after being in use for
some time, it should be disassembled, cleaned and reassembled. If the locknut (B) is
loosened a minimum amount before removing adjusting nut (A), it will assist in adjusting the
pressure setting on reassembly.