cashco 2171 Installation, Operation & Maintenance Manual - Page 4
Browse online or download pdf Installation, Operation & Maintenance Manual for Controller cashco 2171. cashco 2171 8 pages. Back pressure / relief regulators
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10. Reassemble diaphragm subassembly by
plac ing pis ton O-ring (13), diaphragm(s)
(10), pres sure plate (3) and lock washer (6)
over thread ed post of piston(12). Assure the
pres sure plate (3) is placed with curved outer
rim down next to the diaphragm (10) surface.
Place a thread sealant com pound similar to
Loctite #271 on the threads of the piston's
post (12) prior to tightening the pressure plate
nut (7) to the fol low ing torque values:
Sizes
Diaphragm
ALL
Composition
11. For metal diaphragm(s) (10), place dia phragm
gas ket (11) 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 (16) over the pressure
plate nut (7) of the diaphragm subassembly.
13. Place multipurpose, high temperature
grease into de pres sion of spring button (4)
where ad just ing screw bears. Set spring
button (4) onto range spring (16); assure
spring button is laying flat on spring.
14. Rotate the spring chamber (2) CW by hand
into the threaded portion of the body (1)
as sur ing not to cross thread. NOTES: Inspect
and clean threads prior to reassembly. For
the Model 2171 apply an appropriate thread
lubricant to the spring chamber (2) threads
prior to re as sem bly to prevent seizing
together with body (1). Con tin ue hand
rotating CW until firm ly seated against the
upper di a phragm gasket (11). Tighten the
spring chamber (2) and body (1) connection
to the following torque value: All sizes - 30-35
Ft. lbs (41-47 Nm).
15. Reinstall ad just ing screw (5) with locknut (8)
into the spring chamber (2).
16. Pressurize body with air and spray liquid leak
de tec tor around body (1) and spring cham ber
(2) to test for leakage. Ensure that an inlet
pres sure is maintained 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 Re place ment - Model 2171:
1. Procedures are the same as Model 1171.
2. For SST body (1) and SST spring chamber
(2), use thread lubricant to minimize po ten tial
of seizing threads.
4
Torque
Metal
60 In-lbs
(6.8 N-m)
15 In-lbs
(1.7 N-m)
D. Special Instructions for Diaphragm Re mov al:
1. If the TFE coated diaphragm is utilized on the
Model 2171, the TFE coating is the wetted
side of the diaphragm.
2. If the Option -2 handwheel is utilized, the
ad just ing screw (5) and locknut (8) are re-
placed with a handwheel (17) and lock nut
(8). With the Option-22 panel mounting w/
handwheel, the ad just ing screw and lock nut
are replaced with a handwheel (17), lock nut
(8) and a panel mounting nut (18).
3. Use only those gaskets manufactured and
sup plied by Cashco, Inc.
E. Piston / Seat Replacement:
1. Trim removal requires that diaphragm
sub as sem bly be removed and disassembled.
Refer to previous pro ce dure, Sec tion VI.B.
2. Inspect inside surface of cylinder wall inside
the body. (NOTE: The cylinder is an integral
part of the body. Replace the regulator should
any damage be noted on the cylinder or seat
surfaces). If there are no signs of erosion/
wear on seating surfaces, piston (12) alone
may be replaced.
If composition seat (14) is damaged or worn,
rotate the set screws (15) CCW to remove.
Grasp the seat and pull it out of the piston(12).
Insert new seat into the end of the piston and
install set screws to hold the seat in place.
3. Clean body (1) cavity. Clean all parts to be
reused.
NOTE:
sup plied as "oxygen clean", Option's 1171-
5-55, 2171-36-55, main te nance must include
a lev el of cleanliness equal to Cashco's
clean ing stan dard #S-1134. Contact factory
for de tails.
4. Use special care cleaning the body (1) and
cyl in der shoulder, as this pressurized joint is
metal-to-metal with no gasket.
5. Reinstall diaphragm subassembly per
Sec tion VI.B., Diaphragm Replacement.
6. Bench test unit for suitable operation. NOTE:
Reg u la tors are not tight shut off devices.
Even if pressure falls below setpoint, a
reg u la tor may or may not develop bubble
tight shut off. In general, tighter shut off can
be ex pect ed with composition seat.
7. Spray liquid leak de tec tor to test for leakage
around body (1) and spring cham ber (2). Test
pressure should be the max i mum allowed by
the range spring (16) at the inlet.
On regulators originally
IOM-1171/2171