Why centrifugal pumps with a head of ≥25m? Is it necessary to install a check valve?
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Principles for installing check valves at the pump outlet. Check valves need to be installed in the following situations: (1) Pumps whose design does not allow reverse rotation. (2) Centrifugal pumps with a head of ≥25m. (3) Pumps in which it is not permissible from a process perspective for the medium to flow back to the suction side of the pump. Check valves may not be required in the following situations: (1) Transfer pumps for media containing solid particles or substances that tend to crystallize. (2) Pumps equipped with a foot valve on the suction side. (3) The pump itself has no restrictions on reverse operation, and the head
For a head of ≥25m, calculate the pressure – it’s over 2 atmospheres. If no such measure is taken, consider the force exerted by the liquid
Then why is it 25 and not 20? Isn’t the static pressure of 20 also two atmospheres? ? ?
Is it fear that the fluid will flow back, causing the components inside the centrifugal pump to rotate in the opposite direction? Or is the pressure resistance capacity of the pump body designed to be no more than 25 meters of water column pressure?
I don’t know how the senior calculated it, but it was set at 25 instead of 20 or 30
It’s usually experience points; it doesn’t mean that 20 or 30 is enough and no further effort is needed.
The original poster is overcomplicating things; you can also set a head of 20 meters.
Check valves in water pump supply systems primarily prevent high-pressure water from flowing back and causing damage to the pump impeller. If, for some reason, the water pump stops operating while the system is in use, the pressure inside the pump disappears, and the high-pressure water connected to the pump’s outlet flows back into the pump. If a check valve is not installed at the outlet of the water pump, high-pressure water will flow back into the pump, causing the pump’s impeller to rotate in the opposite direction due to the impact of that high-pressure water. The impeller is subjected to the impact load of high-pressure water, which can, in severe cases, cause the impeller or other components to become loose or damaged. When the pump starts running again, it may cause the impeller to fly out, posing a serious threat to safe production. When a check valve is installed at the outlet of the water pump, it closes immediately to prevent high-pressure water from flowing back into the pump.
Check valves in water pump supply systems primarily prevent high-pressure water from flowing back and causing damage to the pump impeller
To trust books entirely is better than having no books at all. A check valve can be installed, or it can also be left out; why must the original poster be so persistent?
What is the standard content for this? It should be a recommended standard, not a mandatory one, right?