CLA-VAL
100-01
Installation - Operation - Maintenance
NGE - GE - AE
`
CLA-VAL
Europe
www.cla-val.ch
5
-
HYT001SE
C 11/08
On 6” and smaller valves block and tackle or a power hoist can be used to lift valve cover by inserting proper size eye
bolt in place of the center cover plug. On 8” and larger valves there are 4 holes (5/8” - 11 size) where jacking screws
and/or eye bolts may be inserted for lifting purposes.
Pull cover straight up
to keep from damaging the integral seat
bearing and stem.
COVER CENTER PLUG SIZE
Valve size
NGE
GE
/ AE
Thread Size (NPT)
DN 50
DN 32 - 40
1/4"
DN 65 - 100
DN 50 - 80
1/2"
DN 125 - 200
DN 100 - 150
3/4"
DN 250 - 300
DN 200 - 250
1"
DN 650 - 400
DN 300
1 1/4"
-
DN 350
1 1/2"
DN 500 - 600
DN 400
2"
TYTAN-S
DN 600 - 800
1"
TYTAN-M
DN 900 - 1000
2"
TYTAN-L
DN 900 - 1200
2"
4. Remove the diaphragm and disc assembly from the valve body. With smaller valves this can be accomplished by hand
by
pulling
straight up on the stem so as not to damage the seat bearing.
On large valves, an eye bolt of proper size
can be installed in the stem and the diaphragm assembly can be then lifted with a block and tackle or power hoist. Take
care not to damage the stem or bearings. The valve won't work if these are damaged.
VALVE STEM THREAD SIZE
Valve size
NGE
GE
/
AE
Thread Size (Internal)
DN 50 - 80
DN 32 - 65
10 - 32 UNF
DN 100 - 150
DN 80 - 100
1/4 - 28 UNF
DN 200 - 400
DN 150 - 350
3/8 - 24 UNF
DN 500 - 600
DN 400
1/2 - 20 UNF
TYTAN-S
DN 600 - 800
1/2 - 20 UNF
TYTAN-M
DN 900 - 1000
M20
TYTAN-L
DN 900 - 1200
M20
5. The next item to remove is the stem nut. Examine the stem threads above the nut for signs of mineral deposits or
corrosion. If the threads are not clean, use a wire brush to remove as much of the residue as possible. Attach a good
fitting wrench to the nut and give it a sharp “rap” rather than a steady pull. Usually several blows are sufficient to loosen
the nut for further removal. On the smaller valves, the entire diaphragm assembly can be held by the stem in a vise
equipped with soft brass jaws
before removing the stem nut.
The use of a pipe wrench or a vise without soft brass jaws scars the fine finish on the stem. No amount of careful
dressing can restore the stem to its original condition. Damage to the finish of the stem can cause the stem to bind in the
bearings and the valve will not open or close.
6. After the stem nut has been removed, the diaphragm assembly breaks down into its component parts. Removal of the
disc from the disc retainer can be a problem if the valve has been in service for a long time. Using two screwdrivers
inserted along the outside edge of the disc usually will accomplish its removal. Care should be taken to preserve the
spacer washers in water, particularly if no new ones are available for re-assembly.
7. The only part left in the valve body is the seat which ordinarily does not require removal. Careful cleaning and polishing
of inside and outside surfaces with 400 wet/dry sandpaper will usually restore the seat’s sharp edge. If, however, it is
badly worn and replacement is necessary, it can be easily removed.
Seats in valve sizes 1 1/4” through 6” are threaded into the valve body. They
can be removed with accessory X109 Seat Removing Tool available from the
factory. On 8” and larger valves, the seat is held in place by flat head machine
screws. Use a tight-fitting, long shank screwdriver to prevent damage to seat
screws. If upon removal of the screws the seat cannot be lifted out, it will be
necessary to use a piece of angle or channel iron with a hole drilled in the
center. Place it across the body so a long stud can be inserted through the
center hole in the seat and the hole in the angle iron. By tightening the nut a
uniform upward force is exerted on the seat for removal.
Note:
Do not lift up on the end of the angle iron as this may force the integral
bearing out of alignment, causing the stem to bind.
Содержание CPC 138-01
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