Carrier Water Pipe Sizing
Carrier Water Pipe Sizing
(OP)
I am using an existing 3" plant water line that runs under 40 psig as a source of carrier water to convey a treatment chemical to a water channel approximately 500 feet away. I need to determine if I have enough pressure to get the water and chemical through a new 2" pipeline to the channel. I want to compute the friction losses due to fittings and valves but need a fluid velocity in the 2" line. How do I determine the flow rate in the new pipeline and subsequently the fluid velocity so I can compute these friction losses in terms of velocity heads? Is this an iteritive process?





RE: Carrier Water Pipe Sizing
Use a fluid velocity of 3-6 ft/sec.
RE: Carrier Water Pipe Sizing
Alternately if you have 40PSI available you will get something less than 100 GPM thru your 2"line.
RE: Carrier Water Pipe Sizing
RE: Carrier Water Pipe Sizing
For a velocity of 6 ft/sec (137 gpm) in a 3" dia pipe, that would be a headloss of around 8 feet per 100 feet of pipe. For 500 feet of pipe, assuming a few elbows, that would be a headloss of 40 feet or approximately 17 psi.
For a velocity of 3 ft/sec (30 gpm) in a 2" dia pipe, that would be a headloss of around 3.5 feet per 100 feet of pipe. For 500 feet of pipe, assuming a few elbows, that would be a headloss of 21 feet or approximately 9 psi.
For a velocity of 6 ft/sec (62 gpm) in a 2" dia pipe, that would be a headloss of around 12.2 feet per 100 feet of pipe. For 500 feet of pipe, assuming a few elbows, that would be a headloss of 40 feet or approximately 32 psi.
It looks like if you used the 2" diameter pipeline, it would have 1-1/2 to 2 times the headloss of the 3" diameter pipeline.