ProMinent DHV-U Série Manuel D'utilisation page 54

Troubleshooting
See the figure in "Repairs" for item numbers.
Fault description
Pressure falls below set level
Set pressure cannot be reached. Valve installed wrong way
Pressure increases above the
allowable value
Leaking at the level of the diaph‐
ragm (5)
Leaking from the adjustment
screw (13)
Loud noises when overflowing
Only type M: Manometer display
"0" or stays on a constant value
* If the manometer is faulty, the hole can be temporarily sealed with the blanking plug – see
"Assembly" chapter.
54
Cause
Piston seal (16) dirty
Piston seal (16) defective
Piston seat in the housing is
dirty
Piston seat in the housing is
defective
Diaphragm (5) dirty
Diaphragm (5) defective
The piston guide (10.2)
binds, e.g. due to dirt
The valve is set to too high
an opening pressure
The piston guide (10.2)
clamps due to too high a
media temperature
Contact pressure of the
diaphragm tensioner is too
low.
Diaphragm (5) defective
Valve too small
Manometer defective
Manometer holes blocked
Remedy
Clean the piston seal (16), see
"Repairs"
Replace the piston seal (16),
see "Repairs"
Clean the piston seat, see
"Repairs"
Contact ProMinent
Clean the diaphragm (5), see
"Repairs"
Replace the diaphragm (5) –
see "Repairs"
Turn the valve around, see the
direction arrow.
Dismantle the valve and clean -
refer to "Repairs"
Set the valve to a low opening
pressure
Lower the media temperature
in accordance with the P-T dia‐
gram
Tighten bolts (12). Tightening
torque – see "Repairs"
Replace the diaphragm (5) –
see "Repairs"
Use a larger valve
Replace manometer*
Clean manometer holes