ITT Skotch Trifecta T4405F, Инструкции по установке, эксплуатации и обслуживанию

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ITT
Engineered Valves, LLC Page 20 of 24
Technical Manual No. IOT4400F Effective 8/31/2018
REV LEVEL B
C. Vent Valve
1. Verify the valve is in the full open position.
2. Seal the outlet side of the valve.
3. Pressurize the inlet with a maximum of 50 psig clean dry air, while
monitoring the leak rate from the vent or test port. FM specifies a leak rate
of 24 in
3
/hr (400 cc/hr) or less.
VII. PROOF OF CLOSURE SWITCH TESTING
The intent of the Proof of Closure (POC) switch is to trip during the closure over-travel
(flow < 24 in
3
/hr) portion of the stroke. The switches should change contact state before
flow commences from each individual valve. The Skotch Trifecta
®
Gas valve consist of
two block valves with a corresponding proof of closure switch that must be tested
individually.
The POC switches should be tested after the valve has been leak tested.
A. Inlet Valve POC Switch
1. Testing
a) With the valve in the closed position, verify the normally closed
contacts are made.
b) Very slowly open the valve until the normally closed contacts are
open. At this point stop the movement of the actuator and verify
that flow has not commenced by pressurizing the inlet with a
maximum pressure of 50 psig and monitoring flow from the outlet.
The actuator can be opened slowly by regulating the air pressure to
the actuator.
c) If there is evidence of flow the inlet valve switch needs to be
adjusted.
2. Setting
a) With the valve in the closed position, remove the inlet valve switch
cover.