Changing The Mounting Type To Mounting Using A Crossbeam (Form C To Form B); Pneumatic Connection - Samson 3371 Mounting And Operating Instructions

Installation
nector and screw them tight. Observe
tightening torques.
5.3.2 Changing the mounting
type to mounting using
a crossbeam (form C to
form B)
Note
To mount the crossbeam, a crossbeam
(A17), two serrated lock washers and two
caps are required.
1. Remove the clamps of the stem connec-
tor.
2. Undo the rod nuts (A72) from the bush-
ings (A12).
3. Lift the actuator off the valve bonnet (2).
4. Undo the bushings (A12) from the rod
nuts.
5. Place the crossbeam (A17) on the rods
(A11) in such a way that the bent side of
the actuator housing faces away. Fasten
the crossbeam using the rod nuts (A72)
and serrated lock washers. Observe
tightening torques.
6. Place the caps from below on the rod
nuts (A72).
7. Unscrew the central nut (98) from the
valve bonnet (2).
8. Place the actuator on the valve bonnet
(2). Tighten the central nut (98). Observe
tightening torques.
5-6
9. Fail-safe action "stem extends": position
the stem connector clamps and screw
them tight. Observe tightening torques.
Fail-safe action "stem retracts": apply
pressure to the top diaphragm chamber
until the actuator stem touches the plug
stem. Position the clamps of the stem con-
nector and screw them tight. Observe
tightening torques.

5.4 Pneumatic connection

Determine the lower and upper signal pres-
sure range values before connecting the sup-
ply air:
− The lower signal pressure range value is
the same as the minimum value of the
bench range or operating range (with
preloaded springs).
− The upper signal pressure range value is
the same as the maximum value of the
bench range or operating range (with
preloaded springs).
− For actuator springs that are to be pre-
loaded subsequently, determine the up-
per and lower signal pressure range as
described under 'Spring compression' in
the 'Start-up' section.
a) Actuator stem extends
1. Apply a signal pressure that corresponds
to the lower signal pressure range value
to the connection on the bottom dia-
phragm case.
2. Screw the vent plug into the connection
on the top diaphragm case.
EB 8317 EN