Cashco MPRV-L Pressure Reducing Regulator User Manual
Page 4
IOM-MPRV-L
4
3. Rotate body cap (15) CCW to remove from
body.
4. Remove piston spring (17), piston assembly
(16) and u-cup seal (18). Inspect TFE seating
surface on the piston assembly. NOTE: The
pis ton assembly can not be dis-assembled. If
the TFE seat is damaged, re place the entire
piston assembly.
5. Clean body (1) cavity and all parts to be
reused. NOTE: If regulator was originally
sup plied with Option -5, main te nance must in-
clude a lev el of clean li ness equal to Cashco's
clean ing stan dard #S-1134. Contact factory
for de tails.
6. To re-install trim, slide new u-cup seal (18)
(open end of cup facing up) into recess in
body.
7. Slide the piston assembly into the body, TFE
seat end in fi rst. NOTE: Piston should move
freely up and down within the body cavity.
8. Center the piston spring (17) on top of the
piston.
14. Rotate the spring chamber (2) CW by hand
into the threaded portion of the body (1)
ensuring not to cross thread. Continue ro tat-
ing CW until fi rmly seated against the upper
di a phragm gasket (12). Tighten to 30-35 ft-lbs
(41-47 N-m) torque.
15. Apply Christolube or equivalent to threads of
adjusting screw (3) and install ad just ing screw
with locknut (4) into the spring chamber (2).
C. Trim Replacement:
1. Trim inspection requires that the diaphragm
subassembly be removed. Refer to Sec tion
VI.B. Steps 1-9.
2. To remove piston assembly, secure body
(1) in a vise with the body cap (15) oriented
upwards.
9. Apply Formula 8 thread sealant to the body
cap (15) male threads. Carefully position
the body cap over the piston spring and
engage the threads. NOTE: While engaging
the threads - may encounter minimum resis-
tance from upward force of the piston spring.
With hand pressure continue to press body
cap down evenly until threads are engaged.
Tighten to 30-35 ft.lbs. (41-47 N-m). These
two parts seal metal-to-metal with no gasket.
10. Re-orient body assembly in vise and secure
by the body cap, (body cap oriented down).
11. Reinstall diaphragm subassembly, spring,
etc. per Sec tion VI.B. Steps 10-15.
CAUTION
To prevent damage to the body, use soft jaws when secur-
ing body in a vise. Position body so that vise does not
close over the inlet and the outlet connections.