Had an experienced fire sprinkler contractor run a flow test in a semi-remote area (outside of a large metro area) with a higher residual pressure (45 psi) than static (42 psi). The static pressure was confirmed both before and after the flow test. The flow was relatively low (410 gpm using a 1-3/4" pitoless little hose monster).
I've yet to come across a scenario like this before - could this be due to the city's pumps kicking on during the test, or something else? Wondering if anyone had experience in this regard before. Note: This is a Daily Discussion question submitted anonymously to us by a toolkit member. See the discussion here.
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Nimal Tissa Wijetunga
7/4/2018 10:08:37 am
My experience is always an above ground water tank(not overhead tank) as Private fire main to supply water to Sprinkler system and in that scenario, I found Static pressure is zero or 2 - 3 psi and the residual pressure is between 100 to 140 psi.
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