Cashco 3381 - Manual (Page 4)

IOM-3381/4381 4
(2), use thread lubricant to minimize po ten tial
of seizing threads.
D. Special Instructions for Diaphragm Removal:
1. If the TFE coated diaphragm (13) is utilized on
the Model 4381, the TFE coating is the wetted
side of the diaphragm.
2. If the Option-2 is utilized, the ad just ing screw
(8) and locknut (11) are re placed with a
handwheel (18) and lock nut (11). With the
Option-22 panel mounting w/hand wheel, the
adjusting screw (8) and lock nut (11) are re-
placed with a handwheel (18), lock nut (11)
and a panel mounting nut (19).
3. If the Option-1+6 is utilized with metal dia-
phragms, there will be one diaphragm gasket
(14) on top of and one below the diaphragm(s).
11. For metal diaphragm(s) (13), place dia-
phragm gas ket (14) into body (1) re cess
(none re quired for com po si tion di a phragm).
Set di a phragm sub as sem bly into the body.
12. Place the range spring (17) over the pusher
plate nut (10) of the diaphragm subassembly.
13. Place multipurpose, high temperature grease
into de pres sion of spring button (5) where
ad just ing screw (8) makes contact. Set spring
but ton (5) onto range spring (17); en sure
spring button (5) is laying fl at on top of spring.
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 (14). Tighten to 30-35 ft-lbs
(41-47 N-m) torque value.
15. Reinstall ad just ing screw (8) with locknut (11)
into the spring chamber (2).
16. Pressurize with air and spray liquid leak
de tec tor to test around body (1) and spring
cham ber (2) for leakage. En sure that an outlet
pressure is main tained during this leak test
of at least mid-range spring level; i.e. 20-80
psig (1.4-5.5 Barg) range spring, 50 psig
(3.4 Barg) test pres sure min i mum.
C. Diaphragm Replacement - Model 4381:
1. Procedures are the same as Model 3381.
2. For SST body (1) and SST spring chamber
2. Loosen and remove body cap.
3. Remove piston spring (7), and piston (16).
Note that the seat and piston guide are in-
te gral parts of the body (1) cast ing. Inspect
integral seat and guide for ex ces sive wear,
espe cially at seat sur fac es. Replace if worn,
nicked or de pressed. If integral seat is nicked,
use seat lapping com pound to remove.
Valves equipped with Opt-4 Stabilizer will
have the u-cup stabilizer seal (30) removed
when the piston (16) is removed from body
(1). Remove stabilizer seal (30), if installed.
NOTE: When pis ton (16) assemblies are
used with com po si tion seats, Cashco, Inc.
does not recom mend at tempt ing to remove
the com po si tion seat. If composition seat is
damaged, re place entire piston assembly.
of clean li ness equal to Cash co's clean ing
stan dard #S-1134. For regulators originally
sup plied as “cleaned for Phar ma ceu ti cal and
Food applications” Options 4381-37 and
4381-37S, maintenance must include a level
of clean li ness equal to Cashco cleaning stan-
dard #S-1576. Con tact fac to ry for details.
10. Reassemble diaphragm subassembly by
plac ing pusher plate seal (15) over thread ed
post of pusher plate (4), placing diaphragm(s)
(13) and pressure plate (3) over the threaded
post. Assure the pressure plate (3) is placed
with curved outer rim down next to the dia-
phragm (13) surface. Place a thread sealant
compound on the threads of the push er plate
post (4) prior to tightening the pusher plate nut
(10) to the fol low ing torque values:
Sizes Diaphragm
Torque
In-lbs (N-m)
ALL
Metal 60 (6.8)
Composition 15 (1.7)
CAUTION
To prevent damage to the body, use soft jaws when secur-
ing body in a vise. Position body so that vise closes over
the inlet and the outlet connections.
CAUTION
Option-1+6 contains single di a phragm con struc tion. In
the event of diaphragm fail ure, the process fl u id will mix
with the load ing fl uid. Please alert your rep re sen ta tive so
an al ter na tive product can be se lect ed.
E. Trim Replacement:
1. Secure body (1) in a vise with the body cap
(6) oriented up and the spring chamber (2)
down wards.