Fault Finding - Hawido 1401 Instruction

C. Fault finding
Symptoms
Valve does not open
Valve does not open
(Pressure retention)
Valve does not close
Valve does not close
Loud noise
Erratic operation
Original pressure values not
reached
EWS coating damaged
-7-
Possible cause
One-way flow restrictor blocked
One-way flow restrictor closed
too far
Control valve screw over-
tightened (pressure set too
high)
One-way flow restrictor blocked
Filter in the control line blocked
Air in the control line / upper
valve chamber
Foreign matter in the main valve Carry out service and remove
Diaphragm defective
Valve spindle jammed by
encrustation
Check valve closed
One-way flow restrictor blocked
Unfavourable operating
conditions
Wrong valve size
One-way flow restrictor
incorrectly set
Pressure gauge faulty
Changed operating conditions
Transportation damage,
installation damage
Action
Replace or unscrew the set
screw several times until the
valve functions properly
Unscrew the set screw until the
valve functions properly
Loosen the set screw. Reset the
pressure (see Chapter 6)
Replace, or screw the set screw
fully in and out several times
and then re-set
Clean the filter
Vent
any foreign matter
Carry out a service.
Replace the diaphragm
Carry out service and remove
any encrustation
open
Replace or unscrew the set
screw several times until the
valve functions properly
Change pressure by approx. 0.1
to 0.2 bar. Slightly open or close
the one-way flow restrictor.
Contact the Hawle Customer
Service department.
Have the correct valve size
calculated (contact Hawle)
Set according to Chapter 5
Check or replace pressure
gauge
Reset (see Setting-up
paragraph)
Repair with Hawle two-
component repair set for
coatings