Installation
cessories not fitted with noise-reducing fit-
tings. Both can damage hearing.
Î Wear hearing protection when working
near the valve.
WARNING
WARNING
!
!
Crush hazard arising from moving parts
(actuator and piston stem).
Î Do not insert hands or finger into the
yoke while the air supply is connected to
the actuator.
Î Before working on the control valve, dis-
connect and lock the pneumatic air sup-
ply as well as the control signal.
Î Do not impede the movement of the actu-
ator and piston stem by inserting objects
into the yoke.
Î Before unblocking the actuator and pis-
ton stem after they have become blocked
(e.g. due to seizing up after remaining in
the same position for a long time), re-
lease any stored energy in the actuator
(e.g. spring compression). See associat-
ed actuator documentation.
WARNING
WARNING
!
!
Risk of personal injury due to exhaust air
being vented.
While the valve is operating, air is vented
from the actuator, for example, during
closed-loop operation or when the valve
opens or closes.
Î Wear eye protection when working in
close proximity to the control valve.
5-14
WARNING
!
Risk of personal injury due to preloaded
springs.
Actuators with preloaded springs are under
tension. They can be identified by the long
bolts protruding from the bottom of the actu-
ator.
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.
Tip
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 flow
velocities can damage the valve.
3. Open the valve.
4. Apply the required test pressure.
EB 8075 EN