Quincy Compressor QGS 90, Instruction Book

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10.1.2 Operation
Description
The compressor oil flow is controlled by two thermostatic valves (BV1 and BV2), ensuring reliable
compressor operation and optimum energy recovery.
Bypass valve (BV1) is integrated in the oil filter housing of the compressor and controls the oil
flow through the main oil cooler (Co) of the compressor. Bypass valve (BV2) controls the oil flow
through the oil/water heat exchanger (HE) of the ER unit. Both valves consist of an insert
(thermostat) mounted in a housing.
Flow diagram of compressor with energy recovery system
Reference Designation Reference Designation
BV2 Thermostatic bypass valve of ER
unit OF Oil filter
HE Oil/water heat exchanger (ER
unit) AR Oil separator vessel
E Compressor element BV1 Thermostatic bypass valve in oil
filter housing
Co Oil cooler (compressor) Ca Aftercooler (compressor)
1 Water inlet 2 Water outlet
BV2 starts closing the bypass line over the heat exchanger (HE) at the lower limit of its
temperature range. At the upper limit of its temperature range, the bypass line is completely
closed and all the oil flows through the ER heat exchanger.
On compressors with a maximum pressure lower than 13 bar (175 psi), BV2 starts opening at 40
˚C (104 ˚F) and is completely open at 55 ˚C (131 ˚F).
Instruction book
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