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Does a power cut that causes a Pump to suddenly stop cause a Water hammer?


New member
I am trying to find out if there is a value in a system that would let a pump stop in a controlled way in case of a power cut.
Focus is on Water processes. Waste water and Drinking water.

Are there cases out there that you know of in which a power cut has caused water hammer? I know that it might be valves but could the pump be the culprit ?

I.e would a system that controlled slows down pump have a value in preventing water hammers?

It could also be that the system could keep the pump running until the reserv power system kicks in.
In my experience, particularly in high rise buildings, the power cut is not necessarily the issue. The taps etc continue to be used being gravity fed, but ultimately draining the system of water and creating a vacuum. It is when power is then restored that the biggest danger of water hammer occurs. If the feed pumps/booster set start at 100% speed, this can cause water hammer as the system re-fills. Therefore, if the pumps are variable speed drive, most manufacturers will offer a soft start function where the pumps start-up at a reduced speed for a period of time to allow the system to re-fill.

Below is a link to a "Know How" manual on Water Hammer.