Cashco 1000 Cryogenic - Manual (Page 8)

8 IOM-1000HP-Cryogenic
6. If a composition (soft) seat trim design is uti-
lized, use the following sub-steps:
a. Tighten the "fl ats" of the seat disc screw
(26) within a vise. Firmly hand-grip the
piston (24) and turn CCW to loosen the
seat disc screw (26). If too tight, place a
screwdriver or similar rod with in the pis ton
(24) port holes and rotate. Remove the
piston (24), and inspect for raised burrs
around the port holes if a device is used
to loosen; deburr as required. NOTE: Do
not grip the piston (24) with a wrench.
b. Remove the seat disc (25) and clean the
recessed piston (24) area where the seat
disc (25) is placed. If the edges which
form the recess of the piston (24) are
worn, also replace pis ton (24) and seat
disc screw (26).
c. Place seat disc (25) into recessed end of
piston (24).
d. Place thread sealant on threaded por tion
of seat disc screw (26), and manu ally ro-
tate piston (24) into seat disc screw (26)
(still fi xed in vise) to secure seat disc (25).
Tighten seat disc screw (26) fi rmly. Do
not over-tighten to the point of embedding
the seat disc screw (26) into the seat disc
(25); the seat disc (25) should lay fl at with
no rounded sur face. A mech anical aid is
normally not re quired; hand-tight en ing is
nor mal ly suf fi cient.
7. If utilized, place piston spring (30) over
small er end of cylinder (21).
8. Insert piston assembly (24 metal seat; 24, 25
and 26 comp. seat) into end of cyl in der (21).
9. Place piston collar (23) over end of piston
(24), ensuring that the spherical surface of
the piston (24) and the piston collar (23) bear
against each other.
10. Clean the body (1) cavity thru the open ings.
Clean the "jet area" just inside the body (1)
outlet end thru which the piston (24) projects.
Clean all parts to be re used. NOTE: On regu-
lators originally sup plied with Option 1000-55,
"ox y gen clean", main te nance must in clude a
level of clean li ness equal to Cashco, Inc's.,
cleaning stan dard #S-1134. Contact fac to ry
for details.
11. Use special care cleaning the fl at mating
sur fac es of the body (1) and cylinder (21)
shoulder, as this pressurized joint is metal-
to-metal with no gasket.
12. Lubricate the cylinder (21) threads lightly with
thread sealant. Insert the entire trim stack
into the body (1) opening and screw until
tightly seated. Using the ham mer and wrench
handle, impact the cyl in der (21) into the body
(1). NOTES: 1. Take special pre cau tion to
keep piston collar from getting "cocked" at an
angle when inserted. 2. On 2" brass bodies
(1) with brass trim, a TFE body O-ring (43) is
utilized to seal between the body (1) and the
cylinder (21) sub-as sem bly. This O-ring is not
indicated on Dwg.
13. Inspect the body (1) outlet end to ensure
that the piston (24) is located nearly con-
cen tric to the body (1) bore in the jet area
with clear ance. Under no conditions should
the piston (24) be touching the body (1). Use
two pencils or similar shafts to place in inlet
and outlet ends of valve and alternately push
on each end of the piston (24) to ensure free
move ment. (Total movement is ap proxi matley
1/8".)
14. Bench test unit for suitable operation and seat
leakage. NOTE: Regulators are not nor mal ly
tight shutoff de vic es. Pressure must build
above setpoint for best shutoff.
15. Soap solution test around cylinder (21)-to-
body (1) con nec tion for leakage. Test pres-
sure should be a minimum of 100 psig at the
inlet, or actual service con di tions if higher.