Cashco 123 - Manual (Page 4)

IOM-123-BASIC 4
13. Insert the diaphragm sub-assembly into the
body (1). Rotate the assembly to ensure that
the piston (14) is not binding in the cylinder
(12).
14. Place the range spring (18) onto the retainer
hub of the pressure plate (20).
15. Place multi-purpose, high temperature
grease into de pres sion of spring button (19)
where ad just ing screw bears. Set spring but-
ton (19) onto range spring (18); ensure spring
but ton (19) is laying fl at.
16. Aligning the matchmarks, place spring cham-
ber (2) over the above stacked parts. Install
all bolts (7) and nuts (8). Me chan i cal ly tighten
bolt ing (7 & 8) in a cross pattern that allows
the spring chamber (2) to be pulled down
even ly. Rec om mended torque values are as
follows:
NOTE: Never replace bolting (7 & 8) with
just any bolting if lost. Bolt heads and nuts
are marked with specifi cation identifi cation
mark ings. Use only prop er grades as re place-
ments.
17. Reinstall adjusting screw (17) with locknut
(9).
18. Spray liquid leak detector to test around
bolt ing (7 & 8) and body (1) / spring chamber
(2) fl ang es for leak age. En sure that an inlet
pressure is main tained dur ing this leak test
of at least mid-range spring level; i.e. 20-60
psig (1.4 - 4.1 Barg) range spring, 40 psig
(2.8 Barg) test pressure minimum.
C. Trim Replacement:
1. Trim removal requires the diaphragm sub-
as sem bly be removed. Refer to previous
pro ce dures, Section VI.B.
2. Remove the cylinder sub-as sem bly (12) from
the body (1) by ro tat ing CCW.
3. Inspect the inside surface of the cylinder
(12.1) at four points:
a. Seat (12.2) ring erosion/wear on seat ing
sur faces. If wear is excessive con sider
util iz ing Option-15, stel lited seat sur-
faces.
b. Seat (12.2) wire drawing be tween cyl in-
der (12.1) and seat (12.2) where pressed
in. If wear exists here, consult fac tory.
c. At metal-to-metal surface between body
(1) and cyl in der (12). If wear exists here,
con sult fac tory.
d. Where the piston (24) ribbed guides bear
(guide zone). See Figure 3.
If wear is signifi cant at any of these points,
both the cylinder sub-assembly (12) and
pis ton sub-as sem bly (14, or 14, 15 and 16)
should be re placed. NOTE: Cashco, Inc.
does not rec om mend replacing the seat
(12.2) within the cylinder (12.1). The cyl in der
sub-assembly (12) and pis ton (14) should be
re placed as a set. However, composition seat
discs (15) may be re placed in di vid u al ly.
4. If a composition (soft) seat trim design is
util ized, use the following sub-steps:
a. Tighten the “fl ats” of the seat disc screw
(16) within a vise. Firmly hand-grip the
piston (14) and turn CCW to loosen the
seat disc screw (16). If too tight, place
a wrench on the hex portion of the pis-
ton (14) and rotate. Re move the piston
(14).
b. Remove the seat disc (15) and clean the
re cessed piston (14) area where the seat
disc (15) is placed. If the edges which
form the recess of the piston (14) are
worn, also re place pis ton (14) and seat
disc screw (16).
c. Place seat disc (15) into recessed end
of piston (14).
d. Place thread sealant on threaded por tion
of seat disc screw (16) and manu ally
ro tate pis ton (14) into seat disc screw
(16) (still fi xed in vise) to secure seat
disc (15). Tighten seat disc screw (16)
fi rmly. Do not over-tighten to the point
of em bed ding the seat disc screw (16)
into the seat disc (15); the seat disc (15)
should lay fl at with no round ed sur face. A
me chani cal aid is nor mally not re quired;
hand tightening is nor mally suf fi cient.
5. If stellited seat surfaces are utilized, follow a
pro ce dure similar to the removal of the seat
disc screw (16) with composition seat above.
The stel lited seat cone (36) will, however,
re quire that it be tightened as much as pos-
sible.
Regulator Size Bolt
Size Metal Diaph. Comp. Diaph.
in (DN) Ft-lbs (Nm) Ft-lbs (Nm)
1/2" (15) 3/8-24 25 (34) 22 (30)
3/4"-2" (20-50) 7/16-20 35 (47) 30 (41)
Diaphragm
Regulator Size Piston
Material
Torque
in (DN) Ft-lbs (Nm)
Metal
1/2" (15) Brass 20-25 (27-34)
3/4"-2" (20-50) Brass
35 (47)
1/2"-2" (15-50) SST
Composition
1/2" (15) Brass 20-25 (27-34)
3/4"-2" (20-50) Brass
20 (27)
1/2"-2" (15-50) SST