Selection of the check valve on the low-pressure tank roof vent line-
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To prevent gas backflow and mixing, check valves are installed on the pipelines leading to the flare. There is a problem, however: the flare line itself has backpressure, and a certain pressure is required for the check valve to open; since the pressure in the low-pressure tank is very low, it may not be sufficient to provide this force. If no check valves are used, backflow can have serious consequences. On the other hand, if check valves are installed, the high pressure in the low-pressure tank and its associated pipelines can also cause significant problems. How can this issue be resolved? 1. Choose a check valve with a low opening pressure; opt for the plate type and use it horizontally. What is the typical opening pressure for such valves? It’s possible to process the gate plate so that it can be lower. Are there any other good methods?
I would like to ask: if an exhaust pipe is equipped with a check valve (that allows air to exit but not enter), and liquid flows out of the storage tank, creating negative pressure inside it, how can air not be drawn in?
Same question; looking forward to replies from experts. I would like to use a breathing valve with a recovery tube; I don’t have any samples on hand, and I’m not sure if it will work
Could an expert who understands this give some guidance?
As far as I know, the sealing performance of low-pressure check valves is not very reliable; in my opinion, a liquid-sealed low-pressure check valve should be used! !
This problem seems to cannot be resolved through pipes; the most thorough solution may require adjusting the process. Specifically, for low-pressure tanks, a low-pressure discharge system should be installed.
The check valve installed on the low-pressure tank vent line should be chosen with low operating pressure and reduced resistance in mind. Ordinary metal check valves are relatively heavy, requiring significant force to open them. If your medium permits, consider using a polypropylene check valve, as it is lighter and requires less force to operate.