30
WIKA operating instruction, model CPP120-X
EN
08/2020 EN/DE
8. Maintenance, corrective maintenance and cleaning
8.2.2 Removing the cover
1. Make sure that the pressure supply is depressurised.
2. Disconnect the pressure supply.
3. Unscrew the both test connections
1
from the connection blocks
2
.
4. Remove the hand wheels of the inlet valve
3
, outlet valve
4
and the volume
adjuster
5
.
5. Remove the four plastic cover in the four extreme corners and unscrew the screws
below.
6. Lift cover from back and slide forwards to clear volume adjuster.
8.2.3 Replacing seals on inlet valve and outlet valve
1. Remove valve handles off inlet valve
3
and outlet valves
4
.
2. Unscrew gland nut, and turn spindle anti-clockwise until spindle, gland packing and
sealing ring USIT are removed from the valve body.
3. Remove the old O-ring with a suitable hooked tool.
4. Check that the seal seat is clean and free from any marks, indents etc.
5. Insert new O-ring into the seal seat of the valve body. Make sure that the O-ring is
correctly located int the groove.
6. Re-assemble sealing ring USIT, gland packing and spindle in the correct sequence.
⇒
Make sure that the parts are clean and free of any contamination.
8.2.4 Inlet valve and outlet valve testing procedure
1. Close test connections
1
with blind plugs.
2. Close inlet valve
3
and outlet valve
4
.
3. Connect an external pressure supply to the CPP120-X
⇒
See chapter 6.4.2 "Connection of external pressure/vacuum supply".
4. Open the inlet valve
3
carefully, till the maximum pressure of 120 bar [1,740 psi] is
reached. Then close the inlet valve
3
again.
⇒
The system pressure gauge
6
will indicate the current pressure
5. Observe the system pressure gauge
6
for 5 ... 10 minutes to ensure no pressure is
leaking.
⇒
If the pressure continuously drops down the seal seat of the outlet valve
4
could
be damaged.
6. Check the gland nut of the inlet valve
3
for any leaks with the help of leak detection
spray.
⇒
If a leakage is indicated the seal seat of the valve could be damaged.