Samson 3310 - Conversion Work; Changing the Fail-Safe Action; Changing the Characteristic

9-4 EB 8222-1 EN
Service and conversion work
9.4 Conversion work
9.4.1 Changing the fail-safe
action
a) Type3278PneumaticRotary
Actuator
The fail-safe action of SAMSON Type3278
Actuator can be changed from fail-close to
fail-open or vice versa after the valve has
been installed. In this case, the side where
the rotary actuator is mounted must be
changed (see the 'Installation' section >
'Mounting the actuator onto the valve').
Î Proceed as described in the associated
actuator documentation (uEB8321).
b) Single-actingTypeSRPand
Pneumatic Rotary Actuator
To change the fail-safe action of single-
acting AIR TORQUE TypeSRP Actuator from
fail-close to fail-open or vice versa after the
valve has been installed, the pistons in the
actuator must be changed.
Î Proceed as described in the associated
actuator documentation.
c) Double-actingTypeDAP
Pneumatic Rotary Actuator
The double-acting AIR TORQUE TypeDAP
Rotary Actuator does not move to a dened
end position when the supply air fails. In this
case, conversion to change the fail-safe
action does not apply.
Refer to the mounting and operating instruc-
tions of the rotary actuator used for further
details, for example about changing the
spring range to achieve other actuator
torques.
9.4.2 Changing the character-
istic
Changing the characteristic from equal per-
centage to linear and vice versa can be per-
formed by turning the segmented ball on the
pipeline axis by 180° or by changing the
actuator's direction of rotation.
Î Contact our after-sales service to turn the
segmented ball.
Segmented ball
Linear
Equal
percentage
Fig.9-1: Characteristic of the segmented ball
Note