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WARNING
Removing the valve from the line or disassembling
the valve while there is pressure in the valve body
may result in injury or damage to the valve.
WARNING
Follow all applicable safety regulations and codes and
read and understand all instructions before
undertaking disassembly.
DISASSEMBLY
Figure 525-RD surge relief valves can be serviced
while the body remains connected to the pipeline. A
skilled technician should perform all work. No special
tools are required but due to the weight of large size
valve's components overhead lifting capability is
beneficial.
First ensure there is no pressure within the valve and
operating equipment is tagged and locked out. Refer
to Page 4 for parts identification and location.
Ensure all necessary replacement parts are on hand
before commencing service. Disassemble only as far
as needed to inspect/replace worn parts.
To replace worn/damaged disc seat ring (32):
1.
Mark the position of the counterweights (11)
so they can be reset to their original position
upon reassembly.
2.
Loosen counterweight set screws (12) and
slide counterweights (11) off both arms.
3.
Loosen counterweight arm set screws (10)
and slide counterweight arms (9) off shaft
(6). Be careful not to lose key.
4.
Remove the lever cotter pin (39) and lever
pin (25). Loosen lever set screw (16) and
slide lever (15) off shaft (6). Be careful not to
lose lever key (22).
5.
Remove both packing gland nuts or bolts
(14) and slide glands (7) off shaft (6).
6.
Remove cover bolts (5) and lift off cover (3).
It may be necessary to carefully pry the
cover off the body (1).
7.
Loosen disc arm set screw (13) and
supporting the disc arm assembly, push
shaft (6) out of body.
assembly. Be careful not to lose shaft key
(38).
8.
One shaft bushing (27) and gland packing 8)
should be pushed out with the shaft.
Remove other bushing and gland packing
after shaft has been removed.
9.
Remove seat ring screws (34), seat ring
follower (33) and seat ring (32).
10. Inspect all parts for wear and damage.
Replace all seals, gaskets and any worn
and/or damaged parts.
ASSEMBLY
1a.
Clean and polish all machined bearing and
sealing surfaces. Remove burrs and sharp
Lift out disc arm
3
edges. Apply a light coat of lubricant on
sealing surfaces to assist in the assembly.
2a.
Install new seat ring (32) on disc (2),
replace follower (33) and install seat ring
follower screws (34). Tighten but do not
distort follower ring.
3a.
Insert shaft key (38) into shaft keyway.
Support disc arm assembly in body and
insert shaft so key fits into keyway in disc
arm (31).
4a.
Install both shaft bushings (27) to support
shaft (6). Center disc arm and tighten disc
arm set screw (13).
5a.
Install gland packing (8), glands (7) and
gland nuts or bolts (14). Evenly snug the
gland nuts or bolts (14).
6a.
Install new cover gasket (4) and place
cover (3) on body. Install cover bolts (5)
and tighten in an alternating pattern.
7a.
Place lever key (22) in key slot in shaft (6)
and slide lever (15) onto shaft.
8a.
Install lever pin (25) and lever pin cotter pin
(39). Tighten lever set screw (16).
9a.
Install
keys
counterweight arms onto shaft.
counterweight arm set screws (1).
10a. Slide counterweights (11) onto both arms to
the position previously marked.
counterweight set screws (12).
11a. Slowly open inlet
pressure and check for leaks.
To replace worn piston seal (21):
1.
Remove counterweight arm and disconnect
lever per steps 1 to 4 above.
2.
Note how many turns to close the closing
speed control valve and then open fully.
3.
SLOWLY pull up on the link (17) to extract
the piston (20) from the cushion chamber
(18).
4.
Remove piston seal (21) and inspect piston
and inside of cushion chamber for wear and
score marks. Replace if needed.
5.
Lubricate and install new piston seal (21) on
piston (20).
6.
Remove the cap from the reservoir (24).
7.
Insert piston (20) into cushion chamber (18)
and SLOWLY push down to the bottom. Air
bubbles should be noted leaving the oil.
8.
Pull up on the link and push down until no air
bubbles are seen.
9.
Follow steps 7a to 10a above.
10. Check reservoir oil level is ¾ full, add AW32
hydraulic oil if needed.
11. Replace reservoir cap and adjust closing
speed control valve to ¼ turn open.
12. Slowly open inlet valve to introduce pressure
and check for leaks.
in
shaft
(6)
and
slide
Tighten
Tighten
valve to
introduce
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