Problems with the outlet check valve of centrifugal pumps
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“Vent and drain pipes equipped with valves should be installed on the pump body as well as on the inlet and outlet pipes of the pump. For valves with a diameter of DN50 or larger, it is also possible to drill holes in the valve cover to install drain valves, with the waste fluid being directed to an appropriate drainage system. Have you encountered situations where holes are drilled in check valves for drainage in your work? What are the advantages and disadvantages of this design?
They usually come with exhaust bolts mounted on the flange, or they are used for drainage. Exhausts are usually installed on pipes.
I have seen check valves with vent holes, but I haven’t seen anyone use them in practice in this way. Could the consideration behind such a design be the worry that there might be a gas space at the top of a horizontally installed check valve that cannot be vented through the pipeline? This is just a guess; we still need to wait for the experts to explain it
It’s rare; when the drain valve faces upward, it vents air, and when it faces downward, it drains liquid: lol
The centrifugal pump outlet check valve is usually installed vertically.
There are both vertical and horizontal types, so I specifically emphasized the case of the horizontal type. This of mine is also just a guess.
If not handled properly, it can result in the check valve failing to close properly, leading to the backup pump starting up, or both pumps failing to operate, which could interfere with the shutdown of the unit.
I designed a horizontally mounted check valve with discharge at the lowest point.