Samson 3349 Mounting And Operating Instructions page 54

Servicing
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).
9-2
WARNING WARNING
! !
Risk of personal injury due to residual
process medium in the valve.
While working on the valve, residual me-
dium can flow out of the valve and, depend-
ing on its properties, cause personal injury,
e.g. (chemical) burns.
Î Wear protective clothing, safety gloves,
respiratory protection and eye protec-
tion.
NOTICE
!
Risk of valve damage due to excessively
high or low tightening torques.
Observe the specified torques when tighten-
ing control valve components. Excessive
tightening torques lead to parts wearing out
more quickly. Parts that are too loose may
cause leakage.
Î Observe the specified tightening torques
(see 'Tightening torques' in Annex).
NOTICE
!
Risk of valve damage due to the use of
unsuitable tools.
Î Only use tools approved by SAMSON
(see the 'Tools' section in Annex).
NOTICE
!
Risk of valve damage due to the use of
unsuitable lubricants.
Î Only use lubricants approved by
SAMSON (see the 'Lubricants' section in
Annex).
EB 8048-2 EN