Cashco 6987 - Manual (Page 4)

IOM-6987 4
9. If available, collapse the piston spring (20)
using the special tool from Figure 1. If no
special tool is available, proceed to Step 10.
10. Place new diaphragm gasket (11) and dia-
phragms (10) onto body (1).
11. Place multi-purpose, high temperature grease
into depression of the pressure plate (8) and
spring buttons (4) where the ball bearing (9)
and ad just ing screw (3) bears. In the cen ter
of the di a phragms (10), place the pres sure
plate (8), ball bearing (9), spring but tons (4),
and range spring (6). Ensure spring buttons
(4) are laying fl at.
12. Aligning the matchmarks, place spring cham-
ber (2) over the above stacked parts. Install
fl ange bolts (13). Me chan i cal ly tight en fl ange
bolts (13) in a cross pattern that allows the
spring cham ber (2) to be pulled down even ly.
Tighten all fl ange bolts (13) to the follow-
ing torque value: All Sizes: 45–50 Ft-lbs
(61–68 Nm).
NOTE: Never replace bolting (13) 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.
13. Reinstall adjusting screw (3) with locknut (5).
14. Spray liquid leak detector to test around fl ange
bolts (13) and body (1) / spring cham ber (2)
connection 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. 50-100
psig (3.4 - 6.9 Barg) range spring, 75 psig
(5.2 Barg) test pressure minimum.
C. Renewal Unit Maintenance:
1. Refer to previous pro ce dures, Sec tion VI.B.
steps 1–7 to remove all parts above the re-
new al unit (17).
2. Remove the piston spring but ton (17.3),
piston (17.1) with piston o-ring (19), and the
piston spring (20).
3. Remove the cylinder (17.2) by turning CCW.
4. Inspect seating surfaces of the piston (17.1)
and cylinder (17.2). If necessary, relap the
seat ing sur face or replace renewal unit (17).
5. Clean all parts to be reused according to
own er's procedures. NOTE: On reg u la tors
orig i nal ly sup plied as “spe cial cleaned”, Op-
tion-55, main te nance must in clude a level
of clean li ness equal to Cash co’s clean ing
stan dard #S-1134. On reg u la tors orig i nal ly
sup plied as “spe cial cleaned”, Op tion-56,
main te nance must in clude a level of cleanli-
ness equal to Cash co’s clean ing stan dard
#S-1542. Con tact fac to ry for details.
6. Lubricate the cylinder (17.2) threads lightly
with thread sealant. Install the cylinder
(17.2) into the body (1) and impact until ap-
proximately 100 Ft-lbs (136 Nm) torque value
is reached. This is a metal to metal seal.
7. Install the piston spring (20) into the body
(1) cavity. Place the piston o-ring (19) into
groove of piston (17.1) and install along with
the piston spring button (17.3) into the cylinder
(17.2).
8. Refer to previous procedures, Section VI.B.
steps 8–13 to replace all other parts.
9. Bench test unit for suitable operation. NOTE:
Reg u la tors are not tight shutoff devices. Even
if pressure falls below set point, a regulator
may or may not develop bubble tight shut-
off.
10. Spray liquid leak detector to test around fl ange
bolts (13) and body (1) / spring cham ber (2)
connection 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. 50-100
psig (3.4 - 6.9 Barg) range spring, 75 psig
(5.2 Barg) test pressure minimum.