Hitachi NEXT Series Instruction Manual page 80

9. MAINTAINING THE DSP [How to Service the DSP Air Compressor]
Clean Control Line Filter (Bi-Annually) [Fixed Speed]
7
Control Line Filter
Check Valve – (Replace, 2-Yearly)
8
78
Level Gauge
Rear-upper-
cover
Check valve
cover
Check valve cover
Check valve
① Press the STOP button, and disconnect the power.
② Open the after cooler condensate drain valve to
depressurize the inside of the air compressor. Verify
that no compressed air is discharging out of the drain
valve. The control line filter must to be de-pressur-
ized before conducting any service on the filter.
③ Remove the left door.
④ Remove the control line filter element, and then use
an air nozzle to blow out the inside surface (reverse
flow action) of the control line filter element in order
to remove any dust particles.
⑤ Replace the element at least every 2 years.
Depressurizing the System
１
① Close the stop valve on the discharge air pipe.
② Open the condensate drain valve of the aftercooler to
release the compressed air. Check the LCD and verify
that the DIScharge PRESSure shows 0 MPa (or the
atmospheric pressure).
Removing the Enclosure Panels
2
① Remove the rear-upper-cover.
Disassembling
3
① Disconnect the discharge pipe from the check valve
cover, and remove it.
② Remove the fastening bolts of the check valve cover.
③ Remove the check valve cover, the gasket check valve
and gasket, in that order.
Cleaning and Checking
4
① Sufficiently clean the check valve seat. Make sure
that no rust particles and/or fragmented gaskets are
left on the valve contacting surfaces.
② Sufficiently clean the check valve and check valve
cover. Make sure that no rust particles and/or frag-
mented gaskets are left on the packing contacting sur-
faces.