Swagelok LPRS4 Series, User Manual, Page: 18 / 24

18
Reassembly
RS Series: Standard Diaphragm Sensing
1. Secure the body (10) in a vise.
2. Fit the body plug O-ring (3) and, if present, body plug backup ring (2) onto the body plug (1). Ensure their
orientation is correct per Fig 2.
3. Fit the seat O-ring (9) onto the seat (8).
4. Insert the seat (8) into the body (10). The poppet (7) can be used as an insertion tool if required. Take
care not to damage the seat (8) and poppet (7) if doing this.
5. Fit the O-ring (6) and backup ring (5) onto the poppet (7). Ensure their orientation is correct per Fig 2.
6. Lightly lubricate the poppet O-ring (6) then stack the poppet (7) and poppet spring (4) through the seat (8).
7. Lightly lubricate the body plug (1) threads and assemble over the spring (4) into the body (10). Torque to
37 lbf·ft (50 N·m) while ensuring the body plug O-ring (3) is not pinched.
8. Place the diaphragm plate (11) onto the poppet (7).
9. Place the diaphragm (12) onto the diaphragm plate (11) and locate it in the body (10).
10. Place the bottom spring guide (13) centrally onto the diaphragm (12).
11. Fit the ball (22) into the spring guide (21) and retain in place.
12. Place the set spring (20) and spring guide (21) onto the bottom spring guide (13).
13. Lightly lubricate the cap screws (25). Fit the spring housing (23) over the spring (20) and secure with the
cap screws (25) and washers (24). and torque to 20 lbf·ft (27 N·m).
14. Lightly lubricate the knob assembly stem (26) then insert it into the spring housing (23).
RS Series: Standard Piston Sensing
1. Follow steps 1 through 7 of the RS series standard diaphragm sensing reassembly procedure.
2. Insert the piston plate O-ring (15), piston O-ring (17) and, if present, piston backup ring (18) and piston
guide ring (19) into the piston plate (16). Ensure their orientation is correct per Fig 3-5.
3. Lightly lubricate the piston O-ring (17) then insert the piston (14) into the piston plate (16).
4. Fit the piston plate (16) into the body (10).
5. If present fit the bottom spring guide (13) onto the piston (14).
6. Follow steps 11 through 14 of the RS series standard diaphragm sensing reassembly procedure.
RS Series: Diaphragm Sensing, Self-venting Option
1. Follow steps 1 through 7 of the RS series standard diaphragm sensing reassembly procedure.
2. Fit the self-vent seat O-ring (33) over the self-vent seat (32) then insert the seat into the diaphragm screw
(34). Ensure the chamfered edge of the seat is facing out.
3. Place the diaphragm (12) onto the diaphragm screw (34). Lightly lubricate the threads of the diaphragm
screw (34) then fit the diaphragm plate (11) onto it. Torque to 7 lbf·ft (10 N · m).
4. Insert the O-ring (17) into the self-vent plate (35) and lightly lubricate it.
5. Insert the diaphragm assembly into the self-vent plate (35) per Fig 6.
6. Fit the entire diaphragm and plate assembly onto the body (10) aligning the vent port as desired. Ensure
the diaphragm (12) sits correctly within the body (10).
7. Place the bottom spring guide (13) onto the diaphragm screw (34).
8. Follow steps 11 through 14 of the RS series standard diaphragm sensing reassembly procedure.