Operation - Atlas Copco GA 75 VSD Instruction Book

Although the heat exchanger is made of stainless steel, the water circuit connected to the compressor may
require corrosion inhibitors. Consult the table below to minimise problems due to bad water quality. If in any
doubt, consult Atlas Copco.
Add an anti-freeze product such as ethylene-glycol to the water in proportion to the expected temperature to
avoid freezing.
Recovery water requirements for open water circuits
See section Cooling water requirements.
5.3

Operation

General
The compressor oil flow is controlled by two thermostatic valves (BV1 and BV2), ensuring reliable
compressor operation and optimum energy recovery.
Bypass valve (BV2) is integrated in the ER unit and controls the working of the oil/water heat exchanger (HE)
of the ER unit. Bypass valve (BV1) is integrated in the oil filter housing of the compressor and controls the
working of the main oil cooler (Co) of the compressor. Both bypass valves consist of an insert (thermostat)
mounted in a housing. Bypass valve BV2 has a separate housing, while BV1 is integrated in the oil filter
housing.
Reference
BV2
HE
E
Co
64
Flow diagram of compressor with energy recovery system
Designation
thermostatic bypass valve
of ER unit
oil/water heat exchanger
(ER unit)
compressor element
oil cooler (compressor)
Reference
OF
AR
BV1
Ca
Instruction book
Designation
oil filter
oil separator vessel
thermostatic bypass valve
in oil filter housing
aftercooler (compressor)
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