Cashco BQ - Manual (Page 4)

IOM-BQ 4
15. Insert the diaphragm subassembly into the body
(1). Rotate the assembly to ensure that the piston
is not binding in the cylinder. If nec es sary, buff
piston with Scotch-Brite
® or equivalvent.
16. Place range spring (11) on the pressure plate (10).
17. Place multipurpose, high temperature grease into
depression of spring button (12) where ad just ing
screw bears. Set spring button (12) onto range
spring (11); ensure spring button (12) is laying
fl at.
18. Aligning the matchmarks, place spring cham ber
(2) over the above stacked parts. Install all bolts
(7) and nuts (8) by hand tight en ing. Me chan i cal ly
tighten bolting (7) (8) in a cross pattern that allows
spring chamber (2) to be pulled down even ly. Rec-
om mend ed torques 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 numbers. Use only
prop er grades as replacements.
19. Reinstall adjusting screw (13) with locknut (14).
20. Soap solution test around bolting (7) (8),body (1)
and spring chamber (2) fl anges for leak age. Ensure
that an inlet pressure is maintained during this leak
test of at least mid-range spring level; i.e. 20-75
psig range spring, 50 psig test pres sure minimum.
11. Clean body (1) and diaphragm fl ange. NOTE: On
regulators originally supplied as “cleaned for ox y-
gen service”, Option -5, -36 or -55, main te nance
must include a level of cleanliness equal to Cashco
cleaning stan dard #S-1134. Con tact fac to ry for
details.
12. Place diaphragm gasket (6) on body (1) fl ange, if
required.
13. Reassemble diaphragm subassembly by plac ing
piston (3.1) in a vise (recommend using lead jaws
with vise). Assemble parts on piston cap screw (9)
as follows: pressure plate (10), diaphragm(s) (4),
and piston gasket (5), if re quired. NOTE 1: Apply
a light coat of gasket sealant to gasket. NOTE 2:
Ensure the pressure plate is placed with curved
outer rim down next to the diaphragm (4) sur face.
14. Apply thread sealant compound to the threads
of the piston cap screw (9) and thread into piston
(3.1). Rotate pistion cap screw (9) CW and tighten
to the following torques.
C. Special Instructions for Diaphragm Re place ment:
1. For the Option -1+6 Differential Con struc tion, re as -
sem ble the diaphragm sub as sem bly in Sub-Sec tion
B. Step 12 as follows: assemble parts on piston
cap screw (9), pressure plate (10), piston gas ket
(5), diaphragm(s) (4), piston gasket (5), and push er
plate (23). Refer back to Step 13 for "NOTES".
2. For metal diaphragm(s) (4) only, install a second
diaphragm gasket (6) on the top side of the di a-
phragm. NOTE: Clean the di a phragm fl ange area of
the spring chamber (2) thor ough ly be fore assembly.
3. Utilize a new lock nut seal (22) when installing the
adjusting screw (13) and lock nut (14).
4. Install new closing cap gasket (21), re in stall clos ing
cap (20).
D. Trim Replacement:
1. Trim removal requires that diaphragm sub as sem bly
be removed. Refer to previous pro ce dure Sec tion
VI.B.
2. Using a deep socket with a 24 inch (600mm) le-
ver length, place the socket over the cylinder (3.2)
hex sur fac es. Rotate CCW to re move the cylinder
(3.2).
3. Inspect inside surface of cylinder (3.2) at three
points:
a. Seat ring for erosion/wear on seating sur-
fac es.
b. At metal-to-metal surface between body and
cylinder (3.2). If wear exists here, consult fac-
tory.
c. Where the piston (3.1) ribbed guides bear
(guide zone).
If wear is signifi cant at any of these points, replace
the piston/cylinder assembly (3).
4. Clean the body (1) cavity. Clean all parts to be
reused. NOTE: On regulators originally sup plied
with Option -55, “special cleaned”, main te nance
must include a level of cleanliness equal to Cashco
Specifi cation #S-1134. Contact factory for de-
tails.
5. Use special care cleaning the fl at mating sur fac es
of the body (1) and cylinder (3.2) shoulder, as this
pressurized joint is metal-to-metal with out a gas-
ket.
6. Lubricate the cylinder (3.2) threads lightly with
thread sealant, insert the cylinder (3.2) into the
body (1) and screw CW until tightly seated. Re-
in stall diaphragm subassembly per Section VI.B.,
Diaphragm Re place ment.
DIAPHRAGM TYPE TORQUE
Metal 15 ft-lb (20 N-m)
Composition 12 ft-lb (16 N-m)
REGULATOR SIZE BOLT SIZE METAL DIAPHRAGM COMP. DIAPHRAGM
ALL 5/16" 15 ft-lb (20 N-m) 12 ft-lb (16 N-m)