Flowserve V-378 R1 Edward Equiwedge Gate Valve - Manual (Page 14)

14
Flow Control Division
Edward Valves
Disassembly Procedure of Bonnet Types Area 3
Type I Size
2-1/2 – 3
Class 600,
Figure
Numbers
1611, 1611Y
or 1711Y
Equiwedge
Gate Valves
Illustration No. 7
Valve Type I
Step-by-step disassembly instructions are
described below for each of the five basic
bonnet types. All of the following bonnet
disassembly instructions are arranged in
accordance with the general comments on
pg. 13. Study these pages carefully before
beginning. As disassembly progresses,
place match marks on parts so that the
same orientation can be maintained when
reassembled.
Refer to illustration 7.
1. With the valve in the partially open
position loosen, the gland bolt nuts
and tap the gland (this should relieve
any pressure trapped in the valve).
2. Carefully loosen the yoke hex socket
head cap screws. In case any
trapped pressure remains in valve
after step 1, it will now be relieved.
Remove the yoke cap screws.
3. Loosen the bonnet hex socket head
cap screws.
4. Remove the gland bolt nuts.
5. Rotate the bonnet retainer counter
clockwise on the central bonnet
thread. Close the valve, which when
the gate contacts the seat, will raise
the yoke about 1/2” (13mm). Pry up
the gasket retainer and place three
3/8” (10mm) shims between the
gasket retainer and the body at equal
intervals. Now tighten the bonnet
retainer cap screws in a star pattern
to jack the pressure seal gasket out of
the body. Be careful not to cock the
bonnet. This step may have to be
repeated with thicker shims to finally
break the gasket loose. See the note
below.
6. Once the bonnet is loose, the yoke
can be removed by turning the hand-
wheel to close the valve. When the
threads of the yoke bushing disen-
gage, lift the yoke assembly over the
stem and set on a clean plywood
board or bed of clean rags.
7. The stem, bonnet, and gate assembly
can now be removed, but be careful
to either clamp the gate halves or
hold them securely while withdrawing
parts. See illustration No. 17 pg. 25.
This is necessary because when the
gate halves are disengaged from the
guide grooves in the body, they can
fall off the stem. Place the assembly
on a bed of rags.
Note: These instructions have been
sequenced for a valve in a horizontal
pipeline with the stem in the vertical, up
position. With a different stem orientation,
the steps may have to be slightly modified.
For example, in step 5 if the valves were
in a horizontal pipe with the stem down
when the gasket came free, all the parts
would fall; so at least two of the yoke cap
screws should be engaged into the body
(at least three threads) to prevent this lack
of control. This precaution should also be
observed for other stem orientations.