Samson 3331/BR 31a, Mounting And Operating Instructions

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3 Operation
3.1 Changing the fail-safe
position
The fail-safe position of the Type 3278
Actuator can be changed from “Valve
CLOSED without supply air” to “Valve
OPEN without supply” or vice versa. To pro-
ceed, mount the rotary actuator on the other
side. Refer to section 2.1.2.
The pistons of the Type BR 31a Actuator
(SRP) must be installed in the reverse direc-
tion in the actuator.
Note!
Refer to the Mounting and Operating In-
structions of the rotary actuator used for fur-
ther details such as changing the spring
range to achieve other actuator torques.
4 Maintenance
Note!
Before performing any maintenance
work on the control valve,
depressurize the concerned section
of the plant and drain the process
medium, if necessary.
Wait until the medium has cooled
down, if necessary.
We recommend removing the valve
from the pipeline.
Caution!
On performing any work on the
valve body, first shut off the supply
pressure, disconnect the supply pres-
sure line and remove the actuator.
4.1 Packing
Packing versions for use with temperature
ranges up to 220 °C are self-adjusting.
Packing suitable for higher temperatures up
to 450 °C can be adjusted. This packing
must be adjusted carefully on starting up the
plant by carefully tightening the gland
flange (2).
4.2 Removing the butterfly valve
Note!
On removing the butterfly valve from the
pipeline, make sure that the disc is in the
closed position.
EB 8227 EN
9
Operation