Periodic Testing; Preparation For Servicing Or Conversion Work; Exchanging The Actuator Bonnet; Removing The Cover - Samson EB 8315 EN Mounting And Operation Instructions

Servicing and conversion

9.1 Periodic testing

Depending on the operating conditions,
check the actuator at certain intervals to pre-
vent possible failure before it can occur.
Plant operators are responsible for drawing
up an inspection and test plan.
Tip
Our after-sales service can support you in
drawing up an inspection and test plan for
your plant.
9.2 Preparation for servicing
or conversion work
1. Lay out the necessary material and tools
to have them ready for the intended
work.
2. Put the actuator out of operation (see the
'Decommissioning' section).
9.3 Exchanging the actuator
bonnet
Fig. 9-1 shows the different combinations
(actuator for on/off service, actuator with
positioner and limit switch). The Type 4740
Limit Switch is mounted on the cover of the
actuator. The Type 3724 Positioner is mount-
ed without actuator cover directly to the ba-
sic module of the actuator.
If the actuator is to be replaced or upgraded,
remove the bonnet (cover, positioner or limit
switch) of the actuator.
9-2
9.3.1

Removing the cover

1. Unscrew dome (visual indicator).
2. Unthread both hex socket screws.
3. Remove the cover.
9.3.2 Removing the Type
4740 Limit Switch
1. Remove the limit switch as described in
the Mounting and Operating Instructions
u EB 8357.
2. Leave the cover on the basic module.
9.3.3 Removing the Type
3724 Positioner
1. Remove the positioner as described in
the Mounting and Operating Instructions
u EB 8395.
2. If necessary, unscrew the special screw
(belonging to the positioner).
9.3.4

Mounting the bonnet

Î Make sure that the O-ring and molded
seal are inserted correctly on assembly
(Fig. 9-2).
EB 8315 EN