Attachment According To Vdi/Vde 3847 - Samson 3730-2 Mounting And Operating Instructions

Attachment to the control valve – Mounting parts and accessories
4.3 Attachment according to
VDI/VDE 3847
Type 3730-2xxx0xxxx0x0060xx and
Type 3730-2xxx0xxxx0x0070xx Positioners
with air purging of the actuator's spring
chamber can be attached according to VDI/
VDE 3847.
Type 3730-2xxx0xxxx0x0000xx Positioner
without air purging of the actuator's spring
chamber can be attached according to VDI/
VDE 3847.
This type of attachment allows the positioner
to be replaced quickly while the process is
running by blocking the air in the actuator.
The signal pressure can be blocked in the ac-
tuator by unscrewing the red retaining screw
(20) and turning the air blocker (19) on the
bottom of the adapter block.
Attachment to Type 3277 Actuator (see
Fig. 6)
− Required mounting parts and accesso-
ries: Table 4 on page 52
Mount the positioner on the yoke as shown
in Fig. 6. The signal pressure is routed to the
actuator over the connecting plate (12), for
actuators with fail-safe action "actuator stem
extends" internally through a bore in the
valve yoke and for "actuator stem retracts"
through external piping.
Only the Y1 port is required for positioner
attachment. The Y2 port can be used for air
purging of the spring chamber.
1. Place follower clamp (3) on the actuator
stem, align it and screw tight so that the
28
mounting screw is located in the groove
of the actuator stem.
2. Place the adapter bracket (6) on the po-
sitioner and mount using the screws
(6.1). Make sure that the seals are cor-
rectly seated. For positioners with air
purging, remove the stopper (5) before
mounting the positioner. For positioners
without air purging, replace the screw
plug (4) with a vent plug.
3. For actuators with 355, 700 or 750 cm²,
remove the follower pin (2) on the M le-
ver (1) on the back of the positioner from
pin position 35, reposition it in the hole
for pin position 50 and screw tight.
For actuators 175, 240 and 350 cm²
with 15 mm travel, keep the follower pin
(2) in pin position 35.
4. Insert the formed seal (6.2) in the groove
of the adapter bracket (6).
5. Insert the formed seal (17.1) into the
turnboard (17) and mount the turnboard
to the adapter block (13) using the
screws (17.2).
6. Mount the blank plate (18) to the turn-
board (17) using the screws (18.1).
Make sure that the seals are correctly
seated.
Note
A solenoid valve can also be mounted in
place of the blank plate (18). The orientation
of the turnboard (17) determines the mount-
ing position of the solenoid valve. Alterna-
tively, a restrictor plate can be mounted
(u AB 11).
EB 8384-2 EN