Cashco 123-1-6-S User Manual
INSTALLATION, OPERATION & MAIN TE NANCE MANUAL (IOM)
IOM-123 1+6+S
MODEL 123-1+6+S DIFFERENTIAL
BACK PRESSURE / RELIEF REGULATOR
SECTION I
I. DESCRIPTION AND SCOPE
The Model 123-1+6+S Differential is designed for high pressure liquid or gas applications to Cashco drawing nos.
32934 (NACE construction) and 32935 (Non-NACE construction). It is used to control differential upstream (inlet or
P
) pressure and a loading (P
1
25, and 40).
This is not a safety device and must not be sub sti tut ed for a code approved pres sure safety
relief valve or rupture disc. NOT FOR STEAM SERVICE. NOT FOR OXYGEN SERVICE.
II. INSTALLATION
This unit was designed and is used almost exclusively on compressor and turbo expander seal systems. REFER
TO COM PRES SOR/EXPANDER MANUFACTURER'S MANUAL FOR DE TAILED INSTALLATION, START-UP
AND SHUTDOWN OF THIS UNIT. Install regulator with Inlet (P
in accordance with the directional fl ow arrow cast on body (1).
) pressure to a rotating shaft seal. Sizes are 1/2", 3/4", 1", and 1-1/2" (DN15, 20,
Load
CAUTION A
SECTION II
) pressure coming in the side body (1) connection
1
DIFF
12-13
IIl. PRINCIPLE OF OPERATION
1. Movement occurs as pressure variations reg is ter
on the diaphragm (3). The registering pressure is
the inlet (P
on the "un der neath" side of the diaphragm (3).
The second pressure registered is the loading
(P
LOAD
the diaphragm (3). The range spring (18) determines the differential pres sure setpoint (P
∆ P
= P1 - P
SIZING
P1 > P
LOAD
P1 = P
∆ P
+ P
LOAD
DIFFERENTIAL
= P1 - P
INLET
@ P
Model 123-1+6+S Differential Schematic
) or upstream pressure which reg is ters
1
) pressure in the spring chamber (2) "above"
2
SET
LOAD
1
OUTLET @ P
RANGE SPRING:
SETTING @ P
LOADING FLUID
@ P
DIA PHRAGM
2
SET
LOAD
(Optional)
INLET
@ P
1
SECTION III
). As
SET
inlet (P1) pressure drops, the range spring (18)
pushes the diaphragm (3) down, clos ing the port;
as inlet (P1) pressure increases, the diaphragm
(3) pushes up and the port opens. As the loading (P
tends to follow. An increase in (P
) pressure varies, the inlet (P1) pressure
LOAD
) will increase
LOAD
inlet (P1) pressure by nearly an equal amount ;
a decrease in (P
will decrease the inlet (P1)
LOAD)
pres sure.
2. A complete diaphragm (3) failure will cause the
fl uids to mix in the spring chamber (2) or loading
pressure piping. Reg u la tor action will "fail close"
under a di a phragm (3) failure.
3. Under normal operating conditions, the inlet (P
pressure should be greater than the loading
(P
) pressure by the range spring (P
LOAD
SET
) set-
point.
CAUTION B
Limit any fi eld hydrostatic test to 1-1/2 times the
Maximum Pressure Rat ing (See Ta ble 1). En sure
that the test pressure is applied uniformly to the
body inlet, body outlet, and spring chamber.
)
1
TABLE 1
MAX OPERATING PRESSURES & TEMPERATURE RATING SPECIFICATIONS
NPT and 1500# ANSI Flg. 600# ANSI Flg. 900# ANSI Flg.
DESCRIPTION
Max. Pressure for CS Body/Spg. Ch, 1500 (103) 1500 (103) 1480 (102) 1270 (88) 1500 (103) 1500 (103)
Max. Pressure for SST Body/Spg. Ch. 1500 (103) 1500 (103) 1440 (99) 995 (69) 1500 (103) 1500 (103)
Operating Temperature Range -20°F (-28°C) to +400F (+204C)
100°F
(38°C)
psig (Barg) psig (Barg) psig (Barg) psig (Barg) psig (Barg) psig (Barg)
400°F
(205°C)
100°F
(38°C)
400°F
(205°C)
100°F
(38°C)
400°F
(205°C)
SECTION IV
IV. STARTUP
REFER TO THE COMPRESSOR/EXPANDER MANUFACTURER'S MANUAL FOR DETAILED STARTUP OF
THIS UNIT.
1. On initial start-up with your system op er at ing at
nor mal conditions, check the differential gauge to
ensure the desired differential pressure is being
maintained. If not, go to step 2 and make one fi nal
ad just ment. (This should only be nec es sary on
fi rst start-up.) NOTE: It is crucial that the adjust-
ing screw (17) threads not be dam aged. Do not
use pliers or locking pliers on the adjusting screw
(17).
3-4 complete revolutions. Loosen lock nut (9)
by turning CCW until it is tight (dou ble-nutted)
against closing cap (22). Now the differential
set ting may be adjusted by turning the closing
cap (22) CW to increase differential or CCW
to de crease. After desired setting is reached,
loos en lock nut (9) from clos ing cap (22) and
tighten each se cure ly to spring chamber (2).
b. Remove closing cap (22) from ad just ing screw
2. To adjust differential setting, use one of these two
methods:
(17) by turning CCW. Loosen lock nut (9) by
turning CCW. Turn the adjusting screw (17)
CW to in crease differential pressure or CCW
a. Loosen the closing cap (22) by turning CCW
to de crease. Tight en lock nut (9) and replace
clos ing cap (22).
SECTION V
V. SHUTDOWN
REFER TO THE COM PRES SOR/EXPANDER MAN U FAC TUR ER'S MANUAL FOR DETAILED SHUTDOWN OF
THIS UNIT.
SECTION VI
VI. MAINTENANCE
WARNING 1
SYSTEM UN DER PRES SURE. Prior to performing any
maintenance, isolate the reg u la tor from the system and
relieve all pressure(s). Failure to do so could result in
personal injury.
A. General:
1. Maintenance procedures hereinafter are
based upon removal of the regulator unit from
the pipe line where installed.
2
2. Owner should refer to owner's procedures for
re mov al, handling, cleaning and disposal of
non re us able parts, i.e. gaskets, etc.
3. Refer to Figure 5 for differential regulator
cutaway drawing.
WARNING 2
SPRING UNDER COMPRESSION. Prior to re mov ing
spring chamber subassembly (2), relieve range spring
(18) com pres sion by back ing out the ad just ing screw
(17). Fail ure to do so may result in fl ying parts that
could cause per son al injury.
IOM-123-1+6 +S DIFF
CAUTION C
DO NOT AT TEMPT TO REMOVE ADJUSTING SCREW
(6) FROM TOP OF SPRING CHAM BER (2). The ad just ing screw (6) is threaded up from inside the spring
chamber (2) and the CCW rotation used to relieve
range spring (14) tension will come to a stop. At the
stop ping point, do not apply any torque to ad just ing
screw (6) or dam age may occur and ren der the unit
in op er a ble. See Figure 1.
B. Disassembly:
9
17
2
28
29
2
9
17
28
29
1. Securely install the body (1) in a vise with the
spring chamber (2) directed upwards.
2. Remove closing cap (22).
3. Loosen sealing locknut (9) by rotating CCW.
Relax range spring (18) by turning adjusting
screw (17) CCW.
4. Draw or em bed a match mark be tween body
(1) casting and spring chamber (2) sub as sem bly along fl anged area.
5. Re move all body flange hardware
(7,8,30,41,42).
6. Re move spring chamber (2) and connected
parts, range spring (18) and spring but ton
(19).
CAUTION D
When body fl ange hardware (7,8,30,41,42) is re moved
from this unit it should al ways be re placed with new.
The new hardware (7,8,30,41,42) must have the prop er
grade spec i fi ca tion iden ti fi ca tion mark ings and meet
the following stan dards:
1. All cap screws (7,30) and fl ange stud nuts (8)
must have "heavy hex heads".
2. All studs (41,42) and cap screws (7,30) must
comply with or exceed the requirements of
ASTM-A-193, Grade B7.
3. All fl ange stud nuts (8) must comply with
or exceed the requirements of ASTM A-194,
Grade 2H.
New body fl ange hardware (7,8,30,41,42) may be pur-
chased from Cashco, Inc. or through the OEM.
7. Adjusting screw (17) o-ring inspection:
a. With locknut (9) and closing cap (22) re-
moved, turn adjusting screw (17) CW as
far as possible by grasping the fl ats on
top end. Care ful ly reach in side spring
cham ber (2) and grasp ad just ing screw
(17) by hand. Remove ad just ing screw
(17) by rotating CCW. See Fig ure 1A.
A. Removal
Figure 1: Adjusting screw (17) o-ring inspection.
B. Reassembly
b. Inspect the backup ring (28) and quad ring
(29) for wear. If nicked or torn - replace.
NOTE: Make certain the tefl on backup
ring (28) will insert into spring cham ber (2)
fi rst, before the quad ring (29). (See Fig ure 7 blow-up illustration). Make sure the
quad ring (29) is on straight with no twist.
Use a good grade light weight grease on
the ring seals (28,29).
c. Lubricate adjusting screw (17) threads.
Carefully re in stall adjusting screw (17) up
into the spring cham ber (2) by ro tat ing
adjusting screw (17) CW until top of
ad just ing screw (17) protrudes from top
of spring chamber (2) (See Fig ure 1B.).
NOTE: Care should be taken when hold ing and ro tat ing adjusting screw (6) so the
quad ring (29) and back up ring (28) are
not in ad vert ent ly nicked or torn. Grasp
top of ad just ing screw (17) and turn CCW
until rotation stops (see CAUTION C).
d. Loosely install the lock nut (9) and closing
cap (22).
8. Lift up and remove the diaphragm sub as sem bly con sist ing of the pis ton (14), piston
nut (6), di a phragm (3), di a phragm cov ers (24)
(NACE unit only, Cashco Dwg. 32934), pres sure plate (20), pusher plate (21), seal ing
washer (27), pres sure plate o-ring (31) and
pusher plate o-ring (34). Re move the fl ange
o-ring (32).
9. Loosen piston nut (6) and separate all parts
(3,24 (NACE units only),14,20,21,27,31,34)
of the diaphragm (3) sub as sem bly.
IOM-123-1+6 +S DIFF
3
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