Choosing Piping Size
Choosing Piping Size
(OP)
I am in charge of a project where we are upgrading a wash system for the automotive industry. We are using a Goulds 92SV pump. Specs for the pump as are follows;
Flow at Design: 390 USGPM
Head at Design: 519 FT.
The basic premise of this is that water is pumped to 3 headers measuring 48" in length with 13 nozzles each. Each header must be supplied with 130 GPM. The water pressure exiting the spray nozzle must be at least 200 PSI. The male pipe connection on the nozzle is 1/4" NPT with an equivalent orifice diameter of .149 inches.
I am having difficulty in determining the pipe size for the headers themselve. I just need a rough pipe size for this application as the company that this is being supplied to is going to run the pipping from the pump to the headers. The total distance the pump is going to be is under 5 ft.
If anyone has just a basic way to get a rough size for the piping it would be much appreciated.
Flow at Design: 390 USGPM
Head at Design: 519 FT.
The basic premise of this is that water is pumped to 3 headers measuring 48" in length with 13 nozzles each. Each header must be supplied with 130 GPM. The water pressure exiting the spray nozzle must be at least 200 PSI. The male pipe connection on the nozzle is 1/4" NPT with an equivalent orifice diameter of .149 inches.
I am having difficulty in determining the pipe size for the headers themselve. I just need a rough pipe size for this application as the company that this is being supplied to is going to run the pipping from the pump to the headers. The total distance the pump is going to be is under 5 ft.
If anyone has just a basic way to get a rough size for the piping it would be much appreciated.





RE: Choosing Piping Size
David Simpson, PE
MuleShoe Engineering
In questions of science, the authority of a thousand is not worth the humble reasoning of a single individual. Galileo Galilei, Italian Physicist
RE: Choosing Piping Size
RE: Choosing Piping Size
Basically, to get good distribution (or little maldistribution), the dP of the spray nozzles (200 psi) must be large compared to the dP of the headers (main pipe - 390 gpm) and sub-headers (single pipe - 130 gpm).
So, you need pipe sizes so dP << 200 psi. For 4-5 feet of pipe, that should be easy. Just choose a calculation method and have at it. zdas04 suggested the Hazen-Williams equation. That's a good one for water. There's also some look-up tables in Crane Technical Paper No. 410, the Cameron Hydraulic Data manual, and about a hundred other places.
Just don't use so much pressure drop in 4-5 feet of pipe that you have erosion problems though (too high of a velocity). Design for reasonable velocities, say < 15 ft/sec.
Good luck,
Latexman
To a ChE, the glass is always full - 1/2 air and 1/2 water.
RE: Choosing Piping Size
Thanks again.
RE: Choosing Piping Size
Good luck,
Latexman
To a ChE, the glass is always full - 1/2 air and 1/2 water.
RE: Choosing Piping Size
Use an online calculator:
http://irrigation.wsu.edu/Content/Calculators/Gene...
That would give you 4-Inch for the header pipe and 3-Inch for the three laterals.
RE: Choosing Piping Size
Going to be a pretty substantial power supply and actuator arm.
RE: Choosing Piping Size
Good luck,
Latexman
To a ChE, the glass is always full - 1/2 air and 1/2 water.
RE: Choosing Piping Size
www.met-l-tec.com to see what this is used for.