Cashco MPRV-L Pressure Reducing Regulator - Manual (Page 3)

IOM-MPRV-L 3
A. General:
1. Maintenance procedures hereinafter are
based upon re mov al of the regulator unit from
the pipeline where in stalled.
2. Owner should refer to owner's procedures for
removal, handling, cleaning and disposal of
non reuseable parts, i.e. gaskets, etc.
3. Refer to Figure 1 for view of basic unit and
item number listing of parts.
B. Diaphragm Replacement:
1. Secure body cap (15) in a vise with the spring
chamber (2) oriented upwards.
VI. MAINTENANCE
SECTION VI
6. Using the "fl ats" on the pusher plate (14)
secure the pusher plate in a soft jawed vice.
Rotate pressure plate nut (7) CCW to loosen
and remove nut, lock washer (8), pressure
plate (10), diaphragm(s) (11) and gasket (13).
(If a composition di a phragm is used there is
no gasket (13)).
WARNING
SYSTEM UN DER PRES SURE. Prior to performing any
maintenance, isolate the reg u la tor from the system and
relieve all pres sure. Failure to do so could result in per-
sonal injury.
WARNING
SPRING UNDER COMPRESSION. Prior to re mov ing the
spring chamber, relieve spring com pres sion by back ing
out the adjusting screw. Fail ure to so so may result in
fl ying parts that could cause personal injury.
CAUTION
To prevent damage to body cap, use soft jaws when se-
curng the body in a vise.
2. Relax range spring (6) by turning adjusting
screw (3) CCW until removed from spring
cham ber (2).
3. Loosen spring chamber (2) by placing wrench
on “fl ats” and rotating CCW.
4. Remove spring chamber, spring button (5),
range spring (6) and diaphragm stop (9).
5. Remove the diaphragm subassembly con-
sist ing of the pressure plate nut (7), lock
wash er (8), pres sure plate (10), diaphragm
(s) (11), gasket (13) and pusher plate (14).
NOTE the quan tity of dia phragms (11) in cor-
po rated in the assembly. De pend ing on out-
let pres sure level, multiple metal diaph ragms
may be “stacked”.
Diaphragm Sub as sem bly
7. Inspect pressure plate (10) to ensure no
de for ma tion due to over-pressurization. If
de formed, replace.
8. Remove diaphragm gasket (12).
9. Clean body (1) diaphragm fl ange surface. Do
not scratch diaphragm gasket seating sur face.
NOTE: If regulator was origi nally sup plied
with Option -5, main tenance must in clude a
level of clean li ness equal to Cash co's clean ing
stan dard #S-1134. Con tact fac to ry for details.
10. Reassemble diaphragm subassembly by
plac ing gasket (13), diaphragm(s)(11), pres-
sure plate (10) and lock washer (8) over the
threaded post. Assure the pressure plate is
placed with curved outer rim down next to the
diaphragm (11) surface. Place a thread seal-
ant compound on the threads of the pusher
plate (14) prior to tightening the pressure plate
nut (7) to the fol low ing values:
Diaphragm
Torque
In-lbs (N-m)
Metal 50 (5.6)
Composition 15 (1.7)
11. Place dia phragm gas ket (12) into body (1)
re cess. Place di a phragm sub as sem bly on
top of gasket, nut side up.
12. Place diaphragm stop (9) and range
spring (6) over the pres sure plate nut
(7) of the di
a phragm sub as sem bly.
13. Apply Christolube or equivalent into de pres-
sion of spring button (5) where ad just ing
screw (3) makes contact. Set spring but ton on
top of range spring (6); en sure spring button
is laying fl at on top of spring.