Swagelok LPRS4 Series, User Manual, Page: 17 / 24

17
Disassembly
- The following instructions describe how to fully disassemble the regulator for the purposes of
maintenance and repair.
- Note that not all components listed appear in all regulator configurations.
- Only disassemble the regulator as far as is required to replace the components supplied in the
maintenance kit.
- Discard all components being replaced.
1. Remove the body plug (1), poppet spring (4), poppet (7), and seat (8) from the body (10).
2. Remove the O-ring (3) and, if present, backup ring (2) from the body plug (1).
3. Remove the O-ring (6) and backup ring (5) from the poppet (7).
4. Remove the O-ring (9) from the seat (8).
5. Ensure the knob assembly (26) is backed out and not acting on the set spring (20). It can be fully removed,
if required, by unwinding counterclockwise until it detaches from the spring housing (23).
6. Loosen the cap screws (25) and remove the spring housing (23).
7. Remove the spring guide (21) including the ball (22), set spring (20), and bottom spring guide (13).
8. If present remove the self-vent plate (35) and associated components.
8a. Remove the diaphragm assembly and O-ring (17) from the self-vent plate (35). Unscrew the diaphragm
plate (11) from the diaphragm screw (34) to release the diaphragm (12). Remove the self-vent seat (32)
from the diaphragm screw (34).
8b. Remove the self-vent piston (14), O-rings (17), and backup rings (18) from the self-vent plate (35).
Remove the self-vent seat (32) from the piston (14).
9. Remove the diaphragm (12) and diaphragm plate (11) or piston plate (16) and piston (14).
10. Remove any O-ring (15, 17), backup ring (18), and guide ring (19) from the piston plate (16).
Points of Attention Before Reassembly
- Visually inspect all components for abnormal wear or damage. Replace components in case of doubt.
- All parts must remain clean and undamaged before starting assembly.
- Maintenance kit components will be supplied preassembled where practicable to aid reassembly.
- Swagelok recommends replacing all O-rings removed during disassembly.
- Swagelok recommends that dynamic O-rings should be lightly lubricated per Table 2.
NOTICE
All threaded components must be lightly lubricated per Table 2 before reassembly to avoid
galling of threads.