Arrangement: Check valve + Butterfly valve + Check valve
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I saw a certain arrangement at the site: check valve + butterfly valve + check valve. What is the reason for this? Another question: there is an actuator (actuation element) on the butterfly valve, and this actuator has two thin metal tubes – one connected to the body of the butterfly valve and the other connected to the inlet end of the check valve ahead of it. What does this mean? Thank you all for your guidance
Use differential pressure signal feedback to enable remote monitoring of the valve status
The first question is too vague to answer! The second one. Those two pipes are the pressure pipes of the actuator, which automatically adjust the opening degree of the valve based on the pressure in the inlet section
Thank you. I’d like to add that this pipe is used to connect to the fire water tank, and it seems to lead towards the tank.
The check valve behind the butterfly valve is intended to prevent backflow of the medium; there is no particular requirement for the check valve in front, and it may serve to prevent the latter check valve from failing, though this scenario is unlikely. It might also be considered from the perspective of investment and operation. Replacing gate valves with check valves reduces manual operation.
It would be best to take a picture. Or draw a schematic diagram. Those two metal tubes are likely used to collect pressure signals. It could certainly be used to adjust the opening degree, or it might serve a cutting function. It is also unclear what the executing agency is.
I think it should be a combined backflow prevention valve system: when the pressure upstream suddenly drops, the check valve closes first. To prevent leaks from the check valve, a differential pressure is used to close the butterfly valve, ensuring that no backflow occurs