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Series 77 & 78 Installation, Operating & Maintenance
8. DISASSEMBLY
The following instructions are for off-line disassembly of valves
sizes
1
⁄
2
” to 1” (DN15-DN25)
8.1.
Cycle the valve with the line pressure fully relieved before
attempting to remove the valve from the pipeline, to insure
pressure has been discharged from the valve cavity.
8.2.
Rotate the valve handle to the “open” position (see Para. 5 for
valve handle position).
8.3.
With the valve in the “open” position, loosen all flange bolts.
8.4.
Remove all flange bolts, so the valve body can slide side-
ways from its installed position and be brought out of the pipe
line (see
figure 3
).
8.5.
Slide out the body from between the line flanges.
8.6.
Hold valve body on a vice with the flange entry face up and
remove the body plug from the valve end using an appropriate
Hex key (see
table 2
for Hex key dimensions).
8.7.
Remove and discard the seat ring and body seal. Be careful
not to damage the sealing surfaces.
8.8.
Turn handle to the “closed” position and slide the ball out from
the body. Set the ball aside in a clean and secure area for reuse.
8.9.
Remove the handle nut, serrated washer, and handle, locking
clip, stem nut, disk springs and follower. Place all removed
components, in a clean and secure area.
8.10.
Push the stem down into the body cavity and remove it (do
not damage the body core). Discard the stem thrust seal and
gland packing, care taken not to scratch or nick the stem bore
area of the body. Clean the stem and stem bore area.
8.11.
Remove seat ring from the valve body.
9. ASSEMBLY
The following instructions are for off-line assembly of valves
sizes
1
⁄
2
” to 1”. (DN15-DN25)
9.1.
Place a seat in the valve body with the round profile facing
the core cavity.
9.2.
Lubricate the new stem thrust seal, bearing and packing, with
appropriate lubricant (Molykote 33 - thin smear). Place the
stem thrust seal on the stem.
9.3.
Insert the stem in horizontal position into the body center
section, with the threaded side first and carefully guide it up
through the stem bore.
9.4.
Holding the stem up, insert the new packing over the stem
and into the stem bore. Place the follower and two disc
springs onto the stem. The first spring’s convex facing down,
and the second spring convex facing up.
9.5.
Thread the stem nut onto the stem. Tighten the stem nut to
the torque figures (
Table 1
).
9.6.
Place the locking clip on the stem nut by adjusting the
orientation of the nut (in the clockwise direction).
9.7.
If required, place the handle, serrated washer and thread the
handle nut on the stem. Tighten the handle nut, while holding
the handle.
9.8.
close the body plug hand tight until it fully stopped
9.9.
mark a straight line that cross the plug and the valve flange
facing.
9.10.
In the next steps the line marked on the flange facing will be
the indication for proper assembly.
9.11.
Remove the plug from the valve body.
9.12.
Bring the handle to the closed position to insert the ball.
9.13.
Place the ball in the valve body until the stem tongue is
engaged, and turn the handle so the valve is at open position,
to prevent the ball from falling out.
9.14.
Place the new body seal and new seat ring in the body.
9.15.
Close the body plug, with appropriate hexagonal key (See
Table 2
), until the line specified in 9.8 is aligned.
9.16.
Ease back the body assembly between line flanges, taking care
not to score faces or damage seals, and reinstall body bolts.
9.17.
To prevent galling of threads of bolts or nuts, lubricate threads
with an anti-galling compound.
Slide appropriate gaskets between the valve flange and
the line flange
9.18.
Tighten evenly the flange bolts.
9.19.
Leave the valve in the open position for line flushing.
10. DISASSEMBLY
The following instructions are for off-line disassembly of valves sizes
1 ½” to 8”. (DN40-DN200)
10.1.
Cycle the valve with the line pressure fully relieved before
attempting to remove the valve from the pipeline, to insure
pressure has also been discharged from the valve cavity.
10.2.
Loosen all flange bolts. Before removing the valve, allow the
fluid to drain from the valve ports.
10.3.
Remove all but one flange bolt on either side of valve, so the
valve body can swing away from its installed position and be
brought out of the pipe line. Make sure there is no load on
the flange before removing the remaining bolts and valve. If
needed, use a lever to release the bolts.
10.4.
Clamp the valve in a vice or connect the valve back flange to
a fixture to support it before removing the valve insert.
10.5.
Bring the valve to the closed position.
10.6.
Hold valve body on a vice, remove all body bolts, and place
the valve end aside.
10.7.
To assist removal of parts, tap on the ball from the other valve
end port using a wooden or plastic mallet. Support the insert
and the ball to prevent them from falling out of the body. Pull
out the seat from the insert, taking care not to damage the
sealing surfaces. Set the insert and the ball aside in clean
secure area for reuse.
10.8.
Remove the body seal. Be careful not to damage the sealing
surfaces.
10.9.
Pull out the second seat from the valve cavity, taking care not
to damage the sealing surfaces of the valve.
10.10.
Remove the wrench bolt, wrench pipe, wrench head, gland
nut, indicator stop plate and gland. Place all components
removed, in clean secure area.
