Flowserve V-378 R1 Edward Equiwedge Gate Valve - Manual (Page 15)

15
Flow Control Division
Edward Valves
See illustrations 8 and 9.
1. With the valve in a partially open
position remove the handwheel. The
handwheel nut is locked in position
with a small nylock set screw. This set
screw must be loosened first before
attempting to remove the handwheel
nut. The handwheel is keyed to the
yoke bushing. Remove the handwheel
nut, handwheel and key and set
aside.
2. Loosen the gland bolt nuts and tap
the gland loose from the packing
chamber. This should relieve any
pressure that may be trapped in the
valve.
3. Carefully loosen the yoke cap screws
or hex nuts. In case any trapped
pressure remains in the valve after
step 2, it will not be relieved.
Remove all yoke cap screws or
hex nuts.
4. Remove the gland bolt nuts.
5. Loosen the bonnet hex nuts about
3/8” (10mm) to 1/2” (13mm).
6. Close the valve, which when the gate
contacts the seat, will raise the yoke.
Place three or four shims 3/8”
(10mm) to 1/2” (13mm) thick equally
spaced between the yoke flange and
the body. Now tighten the bonnet
retainer hex nuts in a star pattern to
jack the 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 gas-
ket loose. See Note this page.
7. Once the bonnet is loose the yoke
can be removed. Remove the bonnet
retainer hex nuts. Sling the yoke
through the windows leaving space
to turn the yokebushing and take up
slack in a chain hoist. With a strap
wrench around the top of the yoke
bushing, close the valve, thereby rais-
ing the yoke. Keep a slight tension on
the chain hoist so that the yoke bush-
ing and stem threads are not dam-
aged. Also, the pull point must be in
line with the stem. Raise the yoke in
this manner until the threads are dis-
engaged, then lift away the yoke
assembly. Set the yoke on a clean
plywood board or bed of rags.
8. Valves with stems 1.62” (41.1 mm) to
2” (50.8mm) in diameter are thread-
ed on the top end to accept a 1/2” –
13 eye bolt and those 2” (50.8mm)
in diameter or over to accept a 3/4”
– 10 eye bolt. Screw the eye bolt into
the stem and attach a chain hoist. Lift
the stem, bonnet, and gate out of the
valve but be careful to clamp the
gate halves securely while withdraw-
ing the parts (see illustration No. 17
pg. 25). This is necessary because
when the gate halves are disengaged
from the body guide grooves, the
halves and spacer ring can fall off
the stem. Place the assembly on a
bed of rags.
Note: These instructions have been
sequenced for valve in a horizontal pipe-
line 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 3, if the valve were in
a horizontal pipeline with the stem down,
when the gasket breaks free in step 6, all
the parts would fall; so, at least two of the
yoke cap screws or hex nuts need to be
partially engaged into/onto the body studs
to prevent this. This precaution should also
be observed for other stem orientations.
Disassembly Procedure of Bonnet Types Area 3
(cont.)
Valve Type IIA Valve Type IIB
Illustration No. 8 Illustration No. 9
Type II Sizes
4 - 28 Class
600, Figure
Numbers
1611,1611Y
or 1711Y
Equiwedge
Gate Valves