Leak Test - Samson 3349 Mounting And Operating Instructions

Installation
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 plug stem by inserting objects
into the yoke.
Î Before unblocking the actuator and plug
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.
WARNING
!
Risk of personal injury due to preloaded
springs.
Actuators with preloaded springs are under
tension. This can be identified by the long
bolts protruding from the bottom of the
Type 3271 or Type 3277 Pneumatic Actua-
tors.
Î Before starting any work on the actuator,
relieve the compression from the pre-
loaded springs (see associated actuator
documentation).
5-8
NOTICE
!
Diaphragm damage through the use of an
incompressible medium.
Closing the valve when the shut-off valves
upstream and downstream of the valve are
closed may lead to the diaphragm rupturing
in plants with liquid media flowing through
them.
Î Only close the valve when the shut-off
valves upstream and downstream of the
valve are open.
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 8048-2 EN