Cashco DA5 - Manual (Page 7)

IOM-DA5 7
vise and rotate end-for-end and resecure
in vise using same metal bars.
5. Body Sizes 2-1/2" thru 4":
a. Orient plug (20) with threaded end up-
wards, place into a vise, grasping the seat
disc nut (30); tighten the vise lightly, only
enough to "hold" the plug (20) from ro tat ing
out of the vise. Caution: Over-tight en ing
the vise can distort the seat disc nut (30)
and give bad fi nal torque values.
b. Place a torque wrench on the 3/4" hex
upper end of the plug (20); tighten the
seat disc nut (30) to 40-60 ft-lbs by ro tat ing
CW.
6. Installation of dynamic side seal (27) (See
Figure 1): NOTE: Dynamic side seal (27) for
sizes 2-1/2"-4" is located on the pis ton/guide
bear ing (13). The dynamic side seal can be
in stalled on a work bench without need of a
vise.
a. Type
CP:
1. Stretch o-ring energizer/seal (27.2)
over lower circumference of valve
plug (20), taking care not to "cut"
o-ring en er giz er/seal (27.4). Using
thumbs, work the o-ring en er giz er/
seal (27.4) up and into the groove of
the valve plug (20). NOTE: A very
slight amount of fl uid and elas tomer
com pat i ble lu bri cant is rec om mend ed
as an in stal la tion aid. DO NOT “ROLL”
O-RING.
2. Position TFE cap seal (27.1) ring with
rectangular cross-section at low er end
of valve plug (20). Stretch cap seal
(27.1) over low er end of valve plug
(20) us ing thumbs to work the cap
seal (27.1) onto the valve plug (20).
DO NOT USE A TOOL FOR THIS
STEP. Con tin ue pressing cap seal
(27.1) up wards to wards the groove
until the cap seal (27.1) “snaps” into
the groove of the valve plug (20).
b. Type PR:
1. Wrap corrugated metal piston ring
en er giz er (27.6) over lower cir cum -
fer ence groove of valve plug (20). Us-
ing thumbs work the energizer (27.6)
into the valve plug (20) groove.
2. Spread a piston ring seal (27.5) and
slide over lower circumference groove
of valve plug (20), taking care not to
“cut” piston ring seal (27.5). Using
thumbs, work the piston ring seal
(27.5) into the groove of the valve plug
(20). Repeat this pro ce dure with a
second piston ring seal (27.5). Ori ent/
rotate the "splits" in pis ton ring seals
(27.5) 180° across from each other.
c. Type UC:
1. Stretch u-cup seal (27.3) over upper
cir cum fer ence of valve plug (20), tak-
ing care not to “cut” u-cup seal (27.3)
on the protruding shelf that is part of
the valve plug's (20) groove. Ensure
that the u-cup seal (27.3) is oriented
with the cen ter-open-up wards as
shown in Fig ure 1, as the u-cup seal
(27.3) depends upon the P1-Inlet
Pres sure to pres sure ac ti vate the seal
for prop er seal ing ac tion.
d. Type NO:
1. For “FTC” fl ow direction ap pli ca tions,
it is not required that a dynamic side
seal (27) be installed. (When included
with the dy nam ic seal (27), better
guid ing of valve plug (20) results.)
Type “NO” dynamic seal (27) means
NO dynamic seal.
2. The more common “FTO Reverse”
fl ow direction always requires a dy-
namic side seal (27).
7. Place fl uid compatible thread anti-seize,
Locktite Corp., "Nickel Anti-Seize", or equal
on thread ed por tion of di a phragm cap screw
(7), sizes 1-1/4" and 1-1/2"; or, thread ed post
por tion of valve plug (20), sizes 1/2" – 1" and
2-1/2" – 4". ( NOTE: Regulators cleaned for
ox y gen ser vice should use Fisher Scientifi c
Co., "Fluorolube GR-362", or equal.)
8. Body sizes 2-1/2" thru 4".
a. Place o-ring lower stem seal (14.3) over
upper-end of plug (20) and into groove
in plug (20).
b. Place properly oriented piston/guide bear-
ing (13) over up per-end of plug (20) and
into po si tion on plug (20).
c. Place o-ring middle seal (14.2) over up-
per-end of plug (20) and into groove of
piston/guide bear ing (13).
9. Body sizes 1/2" thru 2".
Place new o-ring mid dle stem seal (14.2) into
groove of valve plug (20) upper surface.
10. Position lower diaphragm pusher plate (10) on/
over upper end of valve plug (20) properly ori-
ented. For composition diaphragm con struc-
tion the “tongue and groove” “ridge” should