Inspection And Replacement Of; Minimum Pressure / Check Valve - Hitachi HISCREW 2000 Series Instruction Manual

8. PERIODIC MAINTENANCE [Minimum Pressure / Check Valve]
8.10 Inspection and Replacement of Minimum Pressure / Check Valve
Z-ring
Check Valve Spring
Check Valve Body
52
8.10.1 Adjustment of Minimum
Adjustment pressure is preset to 0.44 MPa at the
Cap
delivery from the factory.
If some deviation occurs to the control pressure,
readjustment can be done by the following proce-
Adjustment
Screw
dures.
q Open the valve at the compressor's discharge
Lock Nut
Body
w Remove the cap, fix the adjustment screw by a
O-ring
e Fastening the adjustment screw will increase
Pressure
Control
Spring
r When a specified pressure is obtained, fix the
Minimum
Pressure
Valve
8.10.2 Replacement of Minimum
q Press the STOP button.
w Turn the power OFF.
e Close the stop valve on discharge side.
r Wait until the pressure in the compressor de-
t Hook a spanner on a hexagonal portion of the
y There are a control pressure spring, control
u If there is stain on the sheet surface of the ele-
i At this time, be careful so that the face side of
Pressure Valve
side. Set the unit to blow operation and check
the pressure by the pressure gauge.
hexagon wrench, then unfasten the lock nut.
the control pressure, and unfastening will de-
crease.
adjustment screw again with a lock nut, then
fasten the cap again.
CAUTION
Control pressure adjustment must be car-
ried out while the unit is in operation.
Therefore, ask your dealer or Hitachi ser-
vice station for the work.
Pressure / Check Valve
creases to the ambient air pressure.
minimum pressure / check valve body. Do not
unfasten its lock nut portion, remove the body
in whole instead.
pressure valve body, check valve spring, check
valve body left on the element head side. Take
the part out and replace it with a new one, if
required.
ment head side, clean it. Spread grease on the
Z-ring portion of the pressure control valve
body, or thinly spread the lubricant (NEW
A OIL 2000) over the piston sliding
portion or sheet surface O-ring portion of the
check valve body, and reassemble them.
the check valve spring (broader surface to its
bottom).