Cashco DA5 - Manual (Page 9)

IOM-DA5 9
circumferentially press the fi rst (low er)
piston ring seal (27.5) inwards into the
valve plug (20) groove until the fi rst piston
ring seal (27.5) “slips into” the cage (19).
Repeat for the second piston ring seal
(27.5)
c. Type UC: Position the ITA's valve plug (20)
lower end over and into upper end of cage
(19) until the cap seal (27.1) edge touches
the upper lip of the cage (19). While gently
applying force to press the valve plug
(20) into the cage (19), si mul ta neous ly
use hand thumbs to lightly press the u-
cup seal (27.3) inwards into the groove
of the valve plug (20) until the u-cup seal
(27.3) “slips into” the cage (19). DO NOT
USE TOOLS, LU BRI CANT, OR HEAVY
FORCE TO EN GAGE THE U-CUP SEAL
(27.3) INTO THE CAGE (19).
d. Type NO: Position the ITA's valve plug
(20) lower end over and into the cage
(19), allowing plug (20) to enter fully.
8. For composition diaphragm construction,
align diaphragm (9) bolt holes with body (23)
di a phragm bolt holes.
9. Place a small amount of heavy grease into the
adjusting screw (1) threaded opening of spring
chamber (4). Reengage both ad just ing screw
(1) and its lock nut (2) with spring chamber
(4). Allow end of adjusting screw to protrude
into interior approximately 1/2 inch.
10. Place range spring (6) centered on upper
di a phragm pressure plate (8).
11. Place a dab of heavy grease in the recess of
the spring follower (5). Place spring follower
on upper end of range spring (6).
12. Aligning matchmarks and bolt holes, place
spring chamber (4) over range spring (6). If
spring chamber (4) fl ange reaches body (23)
fl ange without a gap, remove and lower ad-
just ing screw (1) deeper into spring chamber
(4) cavity another 1/4 inch. Repeat this pro-
ce dure until the adjusting screw (1) keeps the
two fl anges from touch ing by approximately
1/8 inch.
13. Reinstall all fl ange bolts (11) and nuts (12)
with nameplate (99) located un der one bolt
head. Hand-tighten nuts (12).
NOTE: If a three-ply diaphragm is being used,
it is important that the diaphragm (9) is “pre-
formed” – pulled together to remove as much
entrapped air as possible and allow formation
of a diaphragm (9) convolution. Starting with
the body bolts and nuts (11,12) hand tight ened,
“preforming” can be ac com plished by any one
of the following tech niques:
a. Apply 30-50 psig pressure to the regula-
tor inlet and the regulator outlet.
OR
b. Block the valve inlet and outlet and apply
30-50 psig under the di a phragm through
the 1/4" NPT ex ter nal pres sure sens-
ing connection on the valve di a phragm
fl ange.
AND
c. Leave pressure on through tightening
of bolt ing (11,12).
14. Evenly tighten the body bolting (11,12) in an
alternating cross pattern in one revolution
increments to the following torque value:
If supplied, remove pressure of previous Step
13.
G. Converting Internal/External Sensing:
1. Disassemble the regulator and remove the
diaphragm(s) (9) according to Steps 1-12 in
Part B – Main Regulator Disassembly.
2. To convert from internal to external sensing,
remove the drilled pipe plug (32) and install
a solid pipe plug. Reverse this step for con-
vert ing from external to internal sensing.
3. Reassemble the regulator according to Part
F – Main Regulator Reassembly.
H. Pressure Testing:
1. If a hydrostatic pressure test is per formed,
pressure must be applied uniformly to the
spring chamber, inlet and outlet of body.
2. Inboard Leakage Test (Seat + Dy nam ic Seal
Leakage).
a. Determine test pressure. If upper value
CAUTION
DO NOT HYDROSTATICALLY TEST WITHOUT SPRING
CHAMBER PRESSURIZED. NOT ADHERING WILL DO
PHYSICAL INTERNALS DAMAGE THAT COULD REN DER
THE UNIT INOPERABLE.
Body Size Torque
in. (DN) ft-lb (N-m)
1/2"-2" (15-50) 30-35 (41-47)
2 1/2"-4" (65-100) 45-50 (61-69)