Flowserve V-377 R4 Edward Valves - Manual (Page 35)

Flow Control Division
Edward Valves
11. With a chain hoist mounted in line
with the stem and fastened to the eye-
bolt, pull the stem into firm contact at
the bonnet backseat.
12. Loosen the bonnet retainer cap
screws.
13. Unscrew the bonnet retainer ring.
14. With clean rags and an air hose,
thoroughly clean the top of the valve
and all exposed surfaces of the bon-
net and gasket retainer segments.
This is important.
15. Slack off the chain hoist slightly. If the
bonnet does not drop away from the
pressure-seal gasket, tap gently until
it does. When the bonnet is free,
lower it into the body to clear the
gasket retainer segments.
16. With a copper or brass drive pin, or
a small clean hardwood block, drive
the gasket retainer segments down-
ward to the bottom of the retainer
groove (about 1/16”) in the body.
17. Remove the gasket retainer segments.
18. Lift the bonnet into contact with the
pressure-seal gasket, again using the
chain hoist.
19. Screw back on the bonnet retainer
ring, using shims to provide addition-
al clearance for further upward move-
ment of the bonnet.
20. Use three or four nuts, in a uniform
spacing on the bonnet studs, to pull
the bonnet and pressure-seal gasket
out of the body. All nuts should be
turned uniformly, a fraction of a turn
at a time using a star pattern. It is
possible to damage the valve parts
by cocking the bonnet, so uniform
turning of the nuts is very important.
21. Remove the stem and bonnet assem-
bly. During this process, mark the
spacer ring and pressure-seal gasket
at points (other than sealing surfaces)
corresponding to the previous mark
on the body (see step 8). In laying
the parts aside for inspection, it is
imperative that they be placed care-
fully on a bed of rags or other soft
material to avoid marring any
machined surface, particularly any
seating and sealing surfaces.
Disassembly Procedures for Bonnet Types
(continued)
Illustration No. 25
Type III Bonnet on Piston-Lift Check Valve
SPACER
RING
GASKET
RETAINER
GASKET
BODY
COVER
35