Daily Operation Of Oil Mist Remover; Adjustment Procedure - Hitachi NEXT Series Instruction Manual

3. OPERATION PROCEDURE [Daily Operation of Oil Mist Remover, Adjustment Procedure]

3.6 Daily Operation of Oil Mist Remover

3.6.1 When Setting
Make sure that the pressure gauge
reads as above.
Make sure that the vacuum
indicator does not show a
red mark.

3.7 Adjustment Procedure

3.7.1 Adjusting the Suction Bypass Valve
(For Fixed-Speed Compressor)
The illustration below is an example of water cooler.
Suction throttle valve
Locknut
Seal washer
34
Pressure gauge (psi)
22 to 26
Make sure that the
condensate is not
collected in the
filter bowl.
If the condensate is
collected, push up
the cock to drain
the condensate.
Condensate Drain Cock
Air Intake filter
Adjusting Bolt
(Suction Bypass Valve)
Usually keep the bolt tightened,
but not excessively.
3.6.2 When Stopped
Make sure that the vacuum indicator shows a red mark.
① When dust particles accumulate on the valve plate of
the suction throttle valve, the suction vacuum
pressure may drop and eventually causing the
discharge air temperature to rise.
② The first steps to resolve the lower suction vacuum
pressure are as following. If the unloaded interstage
pressure drops as low as -12 psi (-0.08 MPa) or
discharge air temperature is gradually increased.
A) Clean or replace the air intake filter.
B) Clean the suction throttle valve's valve plate.
③ If the air compressor cannot be shutdown to clean
these parts, turn the adjusting bolt (the suction
bypass valve) counterclockwise to open. This will
allow the air intake and increase the discharge air
pressure to be greater than -12 psi (-0.08 MPa) when
running unloaded.
④ Replace the consumable parts in the air intake filter
and suction throttle valve with new consumable parts
in accordance with the appropriate maintenance
schedule.( 9. Maintenance the air compressor.)
IMPORTANT
The interstage pressure of as low as -12 psi (-0.08 MPa)
during unloading period may increase the discharge air
temperature.