measuring open end pipe flow
measuring open end pipe flow
(OP)
We need to measure the flow and pressures at a pump discharge. The pump is an old turbine style irrigation well pump which pumps through a gate valve and approximately 50 foot in length of old rusty 10 inch steel line, which then empties into an irrigation ditch. The pump is a older Western Lands Roller pump. The company has changed hands several times and we have not been able to obtain a pump curve (still trying). We expect the pump to produce somewhere between 500-1000 gpm. We need to measure several different flows at different pressures, enough to develop a rough pump curve. Our purpose is to determine if there is sufficient flow and pressure from this well to provide fire protection for a rural historic structure, and satisfy our Fire Marshall. There is no other significant usable source of water for fire flows at this site.
We are looking at building a weir or flume in the ditch; possibly tapping the pipe for a pressure gauge, or a pitot tube. An ideas that can save us time, trouble, expense, etc., are appreciated.
We are looking at building a weir or flume in the ditch; possibly tapping the pipe for a pressure gauge, or a pitot tube. An ideas that can save us time, trouble, expense, etc., are appreciated.





RE: measuring open end pipe flow
RE: measuring open end pipe flow
a) The California Pipe Method
b) The Trajectory Method
In the California method, allow flow to emerge freely from the end of the pipe. Measure with a ruler the height of the air gap from the crown of the pipe down to the surface of the flowing water as it emerges from the pipe. You need to look at the flow/discharge curve published for this method to give a direct flow reading.
The trajectory method is similar and involves measuring the top surface of the water at a distance out from the end of the pipe. Again you take a direct measurement using a ruler and read off from the published flow chart.
These charts should be easily obtainable. they are published in CIRIA Report 113 www.ciria.org.uk (I think)
PS both of these methods require that the pipe has a straight length of 8 diameters prior to discharging.
Regards
Andy
RE: measuring open end pipe flow
It was a portable venturi meter for measuring water flow through storm or drainage systems. It had an inflatable collar to seal against the pipe's inner wall and then the dP reading and total flow was read off a hand head unit. Sounds like it would fairly easily fit into the end of your piping.
The other one would be a portable ultrasonic flow meter, I've used these with good accuracy.
RE: measuring open end pipe flow
KRS Services
www.krs-services.com
RE: measuring open end pipe flow
RE: measuring open end pipe flow
Mark
RE: measuring open end pipe flow