cashco 521 설치, 운영 및 유지보수 매뉴얼 - 페이지 7
{카테고리_이름} cashco 521에 대한 설치, 운영 및 유지보수 매뉴얼을 온라인으로 검색하거나 PDF를 다운로드하세요. cashco 521 20 페이지. Total tfe, globe-pattern control valve body iom
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10. Raise the actuator assembly (AA) over stem
(9). Release any ac tu a tor air pressure. Lay
actuator assemby aside on work surface.
D. Body Disassembly:
1. Access to body assembly (BA) internals may
be accomplished with the actuator assembly
(AA) intact with the bonnet (2) (i.e. locknut
(15) is still fully tight ened), or with the body
assembly (BA) separated as per above
para graph V.C. Steps 1-10.
2. Maintenance procedures hereinafter are
based upon the actuator assembly (AA) fully
in ter con nect ed with the valve stem assembly
(9) during disassembly.
3. Secure the body in a vise with the actuator
assembly (AA) oriented vertically upwards.
Place matchmarks between the body (1)
bon net flange and the bonnet (2) flange to
assist in final ori en ta tion when the body is
dis as sem bled and/or the ac tu a tor removed.
4. Secure and rig the actuator assembly (AA)
for a ver ti cal lift using an overhead hoist.
Remove slack from rigging.
5. Loosen all bon net cap screws (14)
ap prox i mate ly 1/4" (6 mm) by rotating CCW
(viewed from above).
6. Raise actuator assembly (AA) with overhead
hoist approximately 1/8" (3 mm).
7. Continue to loosen and remove bonnet cap
screws (14 and lockwashers (13).
8. Using overhead hoist, lift the actuator
as sem bly (AA) with the interconnected
valve stem sub-as sem bly (9), bellows sub-
assembly (8), bonnet (2), bonnet spacer
(19), locknut (15), packing gland nut (5),
packing rings (6), Belleville spring washers
(7), bonnet gas ket (11), plug (3) and plug
retainer (4). Lay this as sem bly down on a
horizontal work surface carefully, so as to
not damage the valve's internals.
9. Make a visual inspection of the body sub-
assembly (1) exterior, which includes two
shell halves (1.1), TFE core (1.2), and four
body cap screws (1.3) with body nuts (1.4)
and lock wash ers (1.5).
NOTE:
DO NOT DISASSEMBLE THE PARTS
OF THE BODY SUB-ASSEMBLY (1)!
IOM-521
The valve body (1) is ma chined after the
shell halves (1.1) have been bolted (1.3, 1.4,
1.5) around the TFE core (1.2). Dis as sem bly
of the body sub-assembly (1) will cre ate
align ment problems during reassembly. The
TFE core (1.2) is not replaceable, except as
a body sub-as sem bly (1).
10. Make a visual inspection of the trim portions
still in ter con nect ed to the actuator assembly
(AA) for ob vi ous problems.
11. Hand-grasp the bellows sub-assembly
(8) and rotate CCW (viewed from plug (3)
end) to removal. Do not use any wrench,
vise, etc., for grasping the bellows sub-
assembly (8)! The bellows (8) should only
be hand-tight.
12. Loosen packing gland nut (5) 2-3 revolutions
out of the bonnet (2) by rotating CCW (viewed
from stem (9) end).
13. Loosen jam nut (20) 1-2 revolutions.
14. Grasp the valve's stem sub-assembly (9)
in the lower area (normally surrounded by
the bellows (8.1)) using soft jawed pliers
to pre vent marring stem surface. Place
a wrench on the hex surface of the swivel
lower knuckle (44) and rotate knuckle CW
(viewed from plug (3) end) until lower knuckle
dis-engages from stem (9). Keep track of
the number of full rev o lu tions to dis-engage
and record here. _______________
15. Retract the stem sub-assembly (9)
down wards through the bonnet (2) until
stopped by locknut (20). Rotate lock nut (20),
CCW until it is removed.
16. Fully withdraw stem sub-assembly (9).
17. Visually inspect parts for wear, general
cor ro sion, localized corrosion, dirty service
fluid, uneven alignment, seat leakage wire
draw ing, excess plug-to-seat loading,
flange fac ings, looseness of plug-to-bellows
con nec tion, primary seal at TFE Core (1.2)
-to-bel lows (8.1) joint, secondary seat at
bonnet gasket (11) (See Figure 9), blisters
on TFE sur fac es, etc.
18. Attempt to determine the reason for a
failure. Evaluate if process conditions need
cor rec tion, if alternate materials are required
for the stem sub-assembly (9), or if effects
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