Hitachi NEXT Series Instruction Manual page 91

Depressurizing the System
2
Aftercooler side
Ball valve (2)
Ⓔ
Ⓕ
Ⓓ
Ball valve
Ⓒ
(1)
9. MAINTENANCE [How to Service the Air Compressor]
Three-way change valve
Ⓑ
Ⓐ
Intercooler side
Before cleaning the drain pipe, intercooler, aftercooler,
control line filter, or replacing the check valve, reduce
the internal pressure to 0 (zero) by opening the
condensate drain. Stop the air compressor and
disconnect the main power. Close the stop valve of the
compressed air discharge. Remove rear panel (1) [Ref
No. 911] and rear panel (3) [Ref No. 913].
(1) Intercooler side
Turn the three-way change valve from Ⓐ to Ⓑ.
(2) Aftercooler side
Turn the ball valve (1) from Ⓒ to Ⓓ. And Turn the
ball valve (2) from Ⓔ to Ⓕ.
Verify that the interstage pressure (INTSTG.P) and
discharge pressure (DIS PRESS) is 0(zero) on the LCD
monitor. In addition, remove the parts slowly because the
pressure is still remained in air pipings due to the wrong
operation or piping works.
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