Oil Mist Remover Daily Operation; Adjusting The Dsp - Hitachi NEXT Series Instruction Manual

3. OPERATING THE DSP [Oil Mist Remover Daily Operation, Adjusting the DSP]

3.6 Oil Mist Remover Daily Operation

3.6.1 When Starting
φ8
Pressure Gauge
Make sure that the pressure
gauge reads as follows:
Make sure that the vacuum
indicator does not show a
red mark.
3.6.2 When Stopping
① Make sure that the vacuum indicator shows a red
mark.
② Verify that the pressure gauge reads 0 (zero).

3.7 Adjusting the DSP

3.7.1 While Operating the DSP Air Compressor
②④
Air Intake Filter
Seal Washer
① When dust particles accumulate on the valve plate of
the suction throttle valve, the suction vacuum pres-
sure may drop and eventually causing the discharge
air temperature to rise.
32
51 to 58 psi
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
①④
Suction Throttle
Valve
Locknut
③
Adjusting Bolt
(Suction Bypass Valve)
Usually keep the bolt
tightened, but not excessively.
② The first steps to resolve the lower suction vacuum
pressure are as following.
A) Clean or replace the air intake filter.
B) Clean the suction throttle valve's valve plate.
Note; If the unloaded interstage pressure drops as
low as -0.08MPa (-12 psi), discharge air tem-
perature will gradually increased.
③ If the DSP 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 geater than -0.08 MPa (-12 psi) 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
For the detail refer to the section 9,
schedule.
Maintenance the DSP.
IMPORTANT
If the discharge pressure becomes lower than -0.08 MPa (-12
psi) during unload operation, shaft sealing function decrease.
3.7.2 Regulating the Oil Pressure
Relief Valve
① Use the relief valve to regulate the oil pressure. To
regulate the oil pressure, open the relief valve cap,
loosen the lock nut, and turn the regulating bolt to
keep the oil pressure at the specified 0.12 to 0.16 MPa
(17 to 23 psi).
・ 0 .12 to 0.16 (17 to 23 psi) when the ambient temper-
ature is 20 degree C or higher.
・ 0 .14 to 0.18 (20 to 26 psi) when the ambient temper-
ature is 20 degree C or lower.
(for V type, adjust at the maximum operating frequency.)
② Turn the regulating bolt clockwise to increase the oil
pressure and vice versa.
③ Tighten the locknut and replace the cap.
IMPORTANT
If the oil pressure is reduced to 0.08 MPa (12 psi) or lower, the oil
pressure sensor will detect it and shut down the DSP air compressor.