Operating Instructions for ERHARD NON SLAM Nozzle Check Valve
Fig. 2.4:
Curing of the sealing agent takes about 5 hours.
2.4 Troubles during operation of the ERHARD NON SLAM Nozzle Check Valve
and remedies
Trouble
Possible Causes
Remedy
Deposits or dirt in the seating zone In case of firm incrustations, clean
seating zone and valve disc/ring
Leakage in the seat
Damage to the coating of the valve
disc/ring
Replace valve disc/ring, see
paragraph 2.3
Clogging and seizing of the spring
Clean spring, in case of very dirty
medium: provide spring protecting
device, for dismantling see
paragraph 2.3
Deposits on guiding stem
Open valve manually several times
until valve can be operated easily
again or dismantle according to
paragraph 2.3 and clean guiding
stem and bore
High head loss
Foreign bodies between valve
disc/ring and internal body
Manually remove foreign body,
dismantling acc. to 2.3
Foreign bodies jammed in the
seating zone at v (referred to DN)
<2 m/s
Increase flow velocity and flush out
foreign bodies
Valve blocked
Foreign bodies jammed in the
seating zone at v (referred to DN)
>2 m/s
Manually remove foreign bodies
Return spring broken
Replacement of spring, see
paragraph 2.3
Increased noise
(closing shocks)
Deposits in the guiding device due
to low flow velocity
Cleaning of the bore.
For dismantling, see paragraph
2.3.
Valves installed in a
wrong way,
contrary to the specified
direction of installation
Pump discharges against closed
valve.
The direction arrow has not been
followed during installation.
Removal of the valve from the
pipeline
Installation into the pipeline, see
1.6.
BA43E000
Juli 2009
Rev.9
ERHARD GmbH & Co. KG
x
D-89502 Heidenheim
x
Postfach 1280
Telefon: (07321) 320-0
(07321) 320 491 E-Mail: info
@
erhard.de
Internet: http://www.erhard.de
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