Cashco MPRV-H Pressure Reducing Regulator - Manual (Page 4)

IOM-MPRV-H 4
the threads. Ensure that the piston spring
fi ts inside the recess in the body cap. NOTE:
While engaging the threads - may encounter
minimum resistance from upward force of the
piston spring. With hand pressure continue
to press body cap down evenly until threads
are engaged. Tighten to 50-55 ft.lbs. (68-74
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 per Sec-
tion VI.B. Steps 10-15.
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
sub as sem bly be removed. Refer to previous
pro ce dure, Sec tion VI.B. Steps 1-8.
2. To remove piston assembly, secure body
(1) in a vise with the body cap (15) oriented
up wards.
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.
3. Rotate body cap (15) CCW to remove from
body.
4. Remove piston spring (17) and piston assem-
bly (16). 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. Clean 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. Clean fl at mating surfaces of body (1) to body
cap (6) shoulder. Be careful not to scratch
either surface.
7. To install trim, carefully lower the piston
assembly (16) down into the body cavatity.
NOTE: Piston should move freely up and
down inside the body.
8. Place the piston spring (17) in the recess on
top of the piston.
9. Apply Formula 8 thread sealant to the threads
on the body cap (6). Carefully position the
body cap over the piston spring and engage