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Thursday, May 18th 2017, 7:09am

Water hammer destroying orbit timers

Hi everyone, I am in the middle of a DIY irrigation system coming from the hose bib. Everything seems to be working on the sprinkler end, but my bib is wrecking my orbit timers on closing of the timer (this happened a few weeks ago on the same bib with no system installed yet). My PSI is around 60, and 9 GPM. I inspected my basement to find the pipe feeding the bib and found it is only 1/2" pipe. I'm starting to think this undersized pipe is the cause of the hammering. Without replacing that entire ~24 ft pipe, is there a way through other more affordable means to stop this from happening? Like a pressure regulator at the bib or something else I'm overlooking?


New Member


Friday, May 19th 2017, 12:17pm

Undersized Piping

A flow of 9+/- GPM is way too much, large for a 1/2" pipe. 3/4" Would be the minimal size, 1" would give you more cushion. However on a 24' run of pipe there is not going to be much water force to develop a water hammer that can damage irrigation equipment. If your pressure is 60 PSI, most likely the problem is with the static as well as operating pressure coming from your source. Chances are that your product requires a lower operating pressure such as 30 PSI to 40 PSI, and a constant 60+PSI creates too much pressure against it. Good luck.

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