Flowserve V-378 R1 Edward Equiwedge Gate Valve - Manual (Page 23)

23
Flow Control Division
Edward Valves
Reassembly Instructions for Valves with Composite Pressure Seal Gaskets Only
It is important to determine that the new
composite pressure seal gasket:, the bon-
net and the body sealing area are in satis-
factory condition before installation. The
following steps will help ensure superior
performance of the gasket.
1. Carefully inspect the body bore and
bonnet O.D. sealing surfaces.
Remove any raised metal from the
entry chambers and gasket chamber
regions. Repair any gouges in the
sealing region in accordance with
the instructions on pg. 10.
2. Inspect the new composite gasket.
Note: All composite gaskets have
cracks and wrinkles in the flexible
graphite. This is a normal result of
the forming process and will not
affect gasket performance.
3. Be sure the anti-extrusion rings are
tightly bonded to the graphitic gas-
ket, so they will not touch the body
during assembly, If any of the anti-
extrusion rings are loose, carefully
scrape away all flexible graphite
left on the anti-extrusion ring surface
and re-bond to the graphite surface
using Loctite 454 or other suitable
contact cement. The ends of the
outer rings should touch after bond-
ing. There should be an approxi-
mate .020 ± .005 inch gap at the
ends of the inner ring.
4. Place the gasket on the bonnet with
the two anti-extrusion rings facing
up as shown in the illustration. The
gasket should fit snugly around the
bonnet, and the gasket O.D. should
not exceed the O.D. of the bonnet.
This will ensure that the gasket does
not catch on the body and “ener-
gize” prematurely.
5. Install the spacer ring on the bonnet
as shown with the wide end toward
the gasket. The valve may now be
reassembled using the assembly
procedures described in the follow-
ing sections for different types of
bonnets, except that special
torquing procedures are required as
described in the following:
IMPORTANT: The composite pressure
seal must remain dry until fully com-
pacted for proper sealing!
6. Once the bonnet and bonnet retain-
er holes have been aligned, lightly
lubricate the fasteners with high-tem-
perature anti-seize lubricant.
Assemble the Belleville washers
under the nuts or capscrews.
Assemble remaining parts as
described in previous sections.
7. Preload the bonnet by pulling up
with a well centered crane load or
with come-alongs.
BELLEVILLE
WASHERS
GASKET
RETAINER
SPACER
RING
COMPOSITE
GASKET
TABLE 7
COMPOSITE GASKET BONNET/COVER
BOLT/NUT PULL-UP TORQUES
(FOR INITIAL PULL-UP)
BOLT SIZE REQUIRED TORQUE
FT-LBS
3/8 30
7/16 45
1/2 70
9/16 100
5/8 135
3/4 220
7/8 350
1 540
1-1/8 770
1-1/4 1100
1-3/8 1500
1-1/2 1700
1-5/8 2300
1-3/4 3200
1-7/8 4200
2 4600