5-16 EB 8052-E EN
Installation
Risk of personal injury due to preloaded
springs.
Actuators with preloaded springs are under
tension. They can be identied by the long
bolts protruding from the bottom of the
actuator.
Î Before starting any work on the actuator,
relieve the compression from the pre-
loaded springs (see associated actuator
documentation).
To test the valve functioning before start-up
or putting back the valve into operation, per-
form the following tests:
5.4.1 Leak test
The plant operator is responsible for per-
forming the leak test and selecting the test
method. The leak test must comply with the
requirements of the national and internation-
al standards that apply at the site of installa-
tion.
Our after-sales service can support you to
plan and perform a leak test for your plant.
1. Close the valve.
2. Slowly apply the test medium to the inlet
space upstream of the valve. A sudden
surge in pressure and resulting high ow
velocities can damage the valve.
3. Open the valve.
4. Apply the required test pressure.
5. Check the valve for leakage to the atmo-
sphere.
6. Depressurize the pipeline section and
valve.
7. Rework any parts that leak (see informa-
tion below under ‘Adjusting the packing’)
and repeat the leak test.
Adjusting the packing
A label on the yoke indicates whether an
adjustable packing is installed (see the
'Markings on the device' section).
Impaired valve functioning due to increased
friction as a result of the threaded bushing
or packing gland being tightened too far.
Î Make sure that the plug or piston stem
can still move smoothly after the thread-
ed bushing or the bolts on the packing
gland have been tightened.
Standard and HT packing (threaded bush-
ing)
1. Tighten the threaded bushing (8) gradu-
ally (by turning it clockwise) until the
packing seals the valve.
2. Open and close the valve several times.
3. Check the valve for leakage to the atmo-
sphere.
4. Repeat steps 1 and 2 until the packing
completely seals the valve.
WARNING
!
Tip
NOTICE
!
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