Series NK/F, NKP/F, NKS/F, NKSP/F, NKL/F, NKLP/F
Page 14
9520-070-en
Revision 10
TM 8361
Edition 10/2010
8
Malfunctions
Flange connection valve/pipe is leaking
Retighten the flange screws to a tightening torque
according to
Section 1.2
. If this does not remedy
the leak, the recommended torques may be
exceeded by 10%.
If this also fails to stop the leak, dismantle and
inspect the valve.
Flange connection main body/body end piece is
leaking
Retighten body screws. See paragraph "Flange
connection valve/pipe is leaking".
Packing is leaking
Retighten packing nuts according to the details in
Section 1.2
.
Ball valve does not operate
Is the actuator being supplied with power?
Is any directional control valve connected correct-
ly?
Is there any foreign matter in the valve?
The ball no longer closes completely
Is the stem deformed?
Is the coupling worn?
With a worm gear or actuator, check whether the
end stops can be re-adjusted. The operating
manuals of the gear and actuator manufacturers
contain accurate instructions.
Never apply force to the lever or use an
extension.
1. Try to get the ball valve working again by mov-
ing the lever to and from.
2. Remove the lever stop and try to switch against
the normal direction of rotation.
3. If actuation is not possible with the max. ad-
missible breakaway torque as per
Section 1.3
,
dismantle ball valve and inspect individual
components.
9
Maintenance
All repair work is to be performed by qualified
personnel using the appropriate tools.
For the arrangement, designation and item
numbers of all parts of the valve, see
Section 10
.
Spare parts are to be ordered with all the details
in acc. with the valve identification.
Only original spare parts may be installed.
To prevent leaks, a regular check of the connec-
tion screws should be made in line with the oper-
ating requirements.
For torques see
Section 1.3
.
When disassembling and assembling the valve,
attention is to be paid to the tables and drawings
in
Section 1 and 10
.
As the body lining
409
is drawn over the
disc/stem unit
221
while warm, this work should
only be carried out by the manufacturer.
Has the pump been shut down, drained and
flushed according to the regulations?
See also
Section 7.3
.
If assembled incorrectly, individual compo-
nents of the valve may be damaged and this
can result in malfunctions during operation.
9.1 Notes for assembly
The flexible inlay
521
expands during assembly.
Do not cut off the overhang, but push back into the
lower and upper part of the shell
120.
Before tightening the body screws
914/1
(on
NKL/NKLP threaded rod
918/1
and hex. nut
920/2
), align the disc/stem unit
221
centrally in the
closed position.
Mark the position of the disc/stem unit
221
against
body lining
409
at the hub, so permitting switching
only to this point during later test switching.
With disc/stem unit in closed position, tighten the
body screws (
914/1
, as well
918/1
and
929/2
) until
the gap between the upper and lower part of the
shell
120
is ca. 5 mm.
Open the valve several times counterclockwise
(when viewing the stem unit) and close again in
the opposite direction. A sealing edge can form in
this way.
Never switch in the other direction of
rotation over the sealing edge!
Tighten the body bolts 1-2 mm when disc in closed
position.
Repeat the previously described process once or
twice.
When finally tightening the body bolts, pay
attention to the torques provided in
Section 1.3
.
Содержание NK/F series
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