ProMinent DHV-U Série Manuel D'utilisation page 51

Dismantling the back pressure valve, see also
the following drawing:
1. Set the back pressure valve in an
upright position.
2. Remove cap (11).
3. Undo locking nut (14) and adjusting
screw (13) until the load on compression
spring (8) is completely released.
The adjustment screw (13) turns
ð
easily.
4. Unscrew the housing screws (12) and
pull out.
5. Lift off the spring dome (2).
6. Take out the thrust washer (4), the
spring collar (7), the spring (8) and the
pressure plate (6) with the steel ball (9)
from the spring dome (2).
7. Remove the diaphragm (5), the sepa‐
rating disc (3) and the piston (10) from
the valve body (1).
Fig. 5: Section through DHV-U PVC, PP, PVDF
Fig. 6: Section through DHV-U SS
Inspect the parts and replace as necessary
1.
2.
3.
P_MOZ_0007_SW
3886-3
Carrying out repairs
Check the diaphragm (5), piston seal
(16) and the connector seals (15) for
changes.
Check the spring (8) for wear.
Check the piston guide hole, the valve
seat sealing surface, the diaphragm
contact surface and the O-ring groove
on the valve body (1) for damage, dirt or
lime scale.
CAUTION!
The back pressure valve can fail
Damaged sealing elements can
lead to a loss of function and
leaking of the back pressure
valve.
If in doubt, replace any altered
sealing elements.
3933x01
P_MOZ_0037_SW
51