Cashco 3381 - Manual (Page 3)

IOM-3381/4381 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, Model 3381 or 4381 for the
basic regulator and Figure 2, Model 3381 or
4381 for the cryo gen ic regulator. Blow-ups of
op tions and the com po si tion seat trim are on
either draw ing.
B. Diaphragm Replacement - Model 3381:
VI. MAINTENANCE
SECTION VI
3. Loosen spring chamber (2) by placing wrench
on “fl ats” and rotating CCW making sure not
to use the fl at where the vent hole is locat-
ed.
4. Remove spring chamber (2), range spring
(17) and spring button (5).
5. Remove the diaphragm subassembly con-
sist ing of the pressure plate nut (10), lock
wash er (9), pres sure plate (3), diaphragm
(13), push er plate seal (15) and pusher
plate (4). NOTE: Refer to the quan tity of
dia phragms (13) in cor po rated per the bill of
ma te ri als listing. De pend ing on outlet pres-
sure level, multiple metal diaph ragms may be
“stacked”.
6. Loosen pusher plate nut (10) and separate
all parts (3, 4, 9, 13 & 15) of the diaphragm
subassembly.
7. Inspect pressure plate (3) to ensure no
de for ma tion due to over-pressurization. If
de formed, replace.
8. Remove diaphragm gasket (14). (If a com-
position di a phragm is used there is no di a-
phragm gasket (14).
9. Clean body (1) and diaphragm fl ange. Do not
scratch diaphragm gasket seating sur face.
NOTE: On regulators origi nally sup plied as
“oxygen clean”, Option s 3381-5 & -55, 4381-
36 & -55, main tenance must in clude a level
Diaphragm Sub as sem bly
V. SHUTDOWN
1. On systems with a bypass valve, and where sys-
tem pressure is to be main tained as the reg u la tor
is shut down, slowly open the bypass valve while
closing the inlet (up stream) block valve. Fully
close the inlet (up stream) block valve. (When on
bypass, the sys tem pres sure must be con stant ly
observed and man u al ly reg u lat ed. Close the
outlet (down stream) block valve.
2. If the regulator and system are to both be shut
down, slowly close the inlet (upstream) block
valve. Close the outlet (downstream) valve only
if reg u la tor re mov al is required.
SECTION V
CAUTION
Do not walk away and leave a bypassed reg u la tor unat-
tended.
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, use soft jaws when securng
the body in a vise. Position so that vise closes over the
inlet and the outlet connections.
1. Securely body (1) in a vise with the spring
chamber (2) oriented upwards.
2. Relax range spring (17) by turning adjusting
screw (8) CCW until removed from spring
cham ber (2).