Flowserve V-378 R1 Edward Equiwedge Gate Valve - Manual (Page 18)

18
Flow Control Division
Edward Valves
Introduction
The reassembly procedures in this manual
are not as detailed as the disassembly
procedures since, in most cases, just the
reverse procedure is used. However, step-
by-step instructions are provided for each
of the five bonnet types. In addition, the
following general points should be
considered:
1. The most important consideration in
the reassembly of pressure seal
valves is cleanliness. All flaky rust
and dirt should be removed from all
parts with a wire brush and emery
cloth. Oil and grease should be
removed with a suitable solvent to
prevent any foreign material from col-
lecting on the sealing and seating
surfaces.
2. All threaded parts should be relubri-
cated, such as cap screws, nuts,
studs, and bonnet retainer threads,
with a product such as “Never-Seez”.
The stem threads should be washed
with solvent, dried, and a new appli-
cation of high temperature EP
(extreme pressure) grease applied to
the threads. See pg. 8 for recommen-
dations.
3. An important feature of Equiwedge
gate valves is the two piece gate with
a spacer ring between the two
halves, illustrated in figure 13A. This
spacer can be increased in thickness
to compensate for material removed
from the seats and gates by normal
or extensive refinishing of these sur-
faces. This is a unique design feature.
For every .005” (.13mm) (total) that
is removed from the seating surfaces,
the gate seats lower in the body
approximately 0.032” (.81mm). This
amount of metal removal will not
require any adjustment to the gate
spacer ring thickness.
But, for example, if 0.050”
(1.27mm) were removed from the
combined seating surfaces, the gate
will seat 0.312” (7.92mm) lower in
the body and this wear can be com-
pensated for by making a new spac-
er ring. In addition, the guide rails
on each gate half will require grind-
ing by half the amount added to the
spacer ring to restore an adequate
amount of clearance. The gate spac-
er ring material is stainless steel type
410 heat treated to 26 to 32 RC.
Reassembly Procedures for Equiwedge Gate Valves
Stem-Gate Spacer Ring Assembly
Illustration No. 13A
STEM
GATE HALF
GATE HALF
SPACER RING