Emerson Bettis RPX Series Installation, Operation And Maintenance Manual page 14

Section 5: Assembly Procedure
May 2021
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
Figure 3
10
Fit bottom thrust washer (13) and internal circlip (25) to bottom recess of body
to locate the shaft assembly.
Fit the O-ring seals (18) on the pistons (3), and grease the rack.
Orientate the output shaft at 45° as in Figure 2.
Insert pistons completely with backing pads (9) with piston legs on left hand side
of the bore when viewed from the O-ring end of the piston (Figure 2), until racks
engages with the pinion and then push gently inward. The actuator is now in the
fully closed position, and the shaft indication should be at -5° (pointing slightly
to the right).
Turn the pinion shaft counterclockwise until it is orientated in line with the major
axis of the actuator body. The shaft is now in the closed position.
Insert the right (close) travel stop bolt (21) together with the O-ring (19), washer
(14) and lock nut (23) until the bolt hits the travel stop cam. Tighten the lock nut.
Turn the shaft counterclockwise through 90° to bring it in line with the center line
of the actuator bore. The actuator is now in the open position.
Insert the left (open) travel stop bolt (21) together with the O-ring (19),
washer (14) and lock nut (23) until the bolt hits the travel stop cam. Tighten
the lock nut. The position of the travel stop bolts need to be verified after valve
assembly and adjusted if required.
Fit end cap gaskets (20) to the end caps (4) using a light smear of grease.
Fit Double-Acting end caps (flat model) to body evenly and tighten the end cap
screws with the recommended torque (Table 1).
Fit position indicator assembly (25) to top of the actuator.
Operate the actuator to open and close positions using compressed air and note
the actual positions. Adjust the travel stops if required following the routine
described in this document. If the required travel is not achieved, refer to the
troubleshooting guide.
Non-standard direction of rotation
Piston Piston
45°
Direction
Direction of
movement
of movement
Installation, Operation and Maintenance Manual
NAMUR
Pinion Pinion NAMUR Body Body
slot slot
±2°
Stopper bolt
Stopper bolt
DOC.IOM.BRX.EN Rev. 2
Piston guide Piston guide O-ring O-ring
Gear mark
Gear mark
indication
indication
Cam
Cam
Assembly Procedure