CLA-VAL
100-01
Installation - Operation - Maintenance
NGE - GE - AE
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CLA-VAL
Europe
www.cla-val.ch
3
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HYT001SE
C 11/08
DIAPHRAGM CHECK (#1)
1. Shut off pressure to the HYTROL Valve by slowly closing upstream and downstream isolation valves.
SEE CAUTION!
.
2. Disconnect or close all pilot control lines to the valve cover and leave only one fitting in highest point of cover open to
atmosphere.
3. With the cover vented to atmosphere, slowly open upstream isolation valve to allow some pressure into the HYTROL
Valve body. Observe the open cover tapping for signs of continuous flow. It is not necessary to fully open isolating valve.
Volume in cover chamber capacity chart will be displaced as valve moves to open position. Allow sufficient time for
diaphragm assembly to shift positions. If there is no continuous flow, you can be quite certain the diaphragm is sound
and the diaphragm assembly is tight. If the fluid appears to flow continuously this is a good reason to believe the
diaphragm is either damaged or it is loose on the stem. In either case, this is sufficient cause to remove the valve cover
and investigate the leakage. (See “Maintenance” Section for procedure.)
FREEDOM OF MOVEMENT CHECK (#2)
4. Determining the HYTROL Valve’s freedom of movement can be done by one of two methods.
5. For most valves it can be done after completing Diaphragm Check (Steps 1., 2., and 3.).
SEE CAUTION!
. At the end of
step 3. the valve should be fully open.
6. If the valve has a CLA-VAL X101 Position Indicator, observe the indicator to see that the valve opens wide. Mark the
point of maximum opening.
7. Re-connect enough of the control system to permit the application of inlet pressure to the cover. Open pilot system cock
so pressure flows from the inlet into the cover.
8. While pressure is building up in the cover, the valve should close smoothly. There is a hesitation in every HYTROL Valve
closure, which can be mistaken for a mechanical bind. The stem will appear to stop moving very briefly before going to
the closed position. This slight pause is caused by the diaphragm flexing at a particular point in the valve’s travel and is
not caused by a mechanical bind.
9. When closed, a mark should be made on the X101 Valve position indicator corresponding to the “closed” position. The
distance between the two marks should be approximately the stem travel shown in chart.
10. If the stroke is different than that shown in stem travel chart this is a good reason to believe something is mechanically
restricting the stroke of the valve at one end of its travel. If the flow does not stop through the valve when in the indicated
“closed” position, the obstruction probably is between the disc and the seat. If the flow does stop, then the obstruction is
more likely in the cover. In either case, the cover must be removed, and the obstruction located and removed. The stem
should also be checked for scale build-up. (See “Maintenance, section for procedure.)
11. For valves 6” and smaller, the HYTROL Valve’s freedom of movement check can also be done after all pressure is
removed from the valve.
SEE CAUTION!
. After closing inlet and outlet isolation valves and bleeding pressure from the
valve, check that the cover chamber and the body are temporarily vented to atmosphere. Insert fabricated tool into
threaded hole in top of valve stem, and lift the diaphragm assembly manually. Note any roughness. The diaphragm
assembly should move smoothly throughout entire valve stroke. The tool is fabricated from rod that is threaded on one
end to fit valve stem and has a “T” bar handle of some kind on the other end for easy gripping.
(See chart in Step 4 of “Disassembly” Section.)
12. Place marks on this diaphragm assembly lifting tool when the valve is closed and when manually positioned open. The
distance between the two marks should be approximately the stem travel shown in stem travel chart. If the stroke is
different than that shown, there is a good reason to believe something is mechanically restricting the stroke of the valve.
The cover must be removed, and the obstruction located and removed. The stem should also be checked for scale build-
up. (See “Maintenance, section for procedure.)
TIGHT SEALING CHECK (#3)
13. Test for seat leakage after completing checks #1 & #2 (Steps 1. to 12.).
SEE CAUTION!.
Close the isolation valve
downstream of the HYTROL Valve. Apply inlet pressure to the cover of the valve, wait until it closes. Install a pressure
gauge between the two closed valves using one of the two ports in the outlet side of the HYTROL. Watch the pressure
gauge. If the pressure begins to climb, then either the downstream isolation valve is permitting pressure to creep back, or
the HYTROL is allowing pressure to go through it. Usually the pressure at the HYTROL inlet will be higher than on the
isolation valve discharge, so if the pressure goes up to the inlet pressure, you can be sure the HYTROL is leaking. Install
another gauge downstream of isolating valve. If the pressure between the valves only goes up to the pressure on the
isolation valve discharge, the HYTROL Valve is holding tight, and it was just the isolation valve leaking.
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TROUBLESHOOTING
The following troubleshooting information deals strictly with the Model 100-01 HYTROL Valve. This assumes that all other
components of the pilot control system have been checked out and are in proper working condition. (See appropriate
sections in Technical Manual for complete valve).
Содержание 90-01
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