Series Series
KNAR/F, KNARP/F, KNAR-D/F, KNARP-D/F,
Page 11
KNAR-S/F, KNARP-S/F
ASME
9520-082-en
Revision 14
TM 9549
Edition 11/2017
7.3 Shutdown
The local regulations are to be observed when
dismantling the valve.
Prior to undoing the flange connection ensure, that the
plant is depressurised and emtied.
Move V-control ball/stem unit into the "half-open
position".
Prior to starting any repair work, the valve is
to be thoroughly cleaned. Even if the valve
has been properly emtied and rinsed,
residual medium may still be found in the valve.
After dismantling, immediately protect the valve
flanges against mechanical damage with flange caps.
See also
Section 6.1
.
Ensure that a remotely actuated actuator
cannot be accidentally switched on.
8 Malfunctions
Flange connection valve/pipe is leaking
Retighten the flange screws to a tightening torque
according to
Section 1.3
. 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 1.3
.
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?
Are the sleeve nuts
512
and setscrew
904/4
tight-
ened?
The V-control ball/stem unit has too much
play/hysteresis.
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. admis-
sible breakaway torque as per
Section 1.4
,
dismantle ball valve and inspect individual
components.
