Maximum suction velocity
Maximum suction velocity
(OP)
What could be the maximum permissible velocity through a pump suction pipe. According to Hydraulic institute standards this is 2.4 m/s. However some of my colleagues say to limit the max. velocity to 1.5 m/s. The suction Pipe run is straight and about 13 ft long. Application is sewage. Maximum flow rate is 2.1 m3/s.
Thanks is advance
Thanks is advance





RE: Maximum suction velocity
You need to analyze the proposed installation with the specific pump and piping layout. You need to verify the Net Positive Suction Head Required by the pump.
http://www.gouldspumps.com/pag_0006.html
http://www.mcnallyinstitute.com/02-html/2-7.html
RE: Maximum suction velocity
Unless there are vortexing or air entrainment issues; there is no reason to make piping any larger; just wasting money.
The only pump internal fluid velocity "rules of thumb" I am aware of are for discharge columns in verticals, where they should be kept above 5fps to keep solids from dropping out and max of around 15 fps to keep from washing out the lineshaft bearings and keeping friction loss in check.
RE: Maximum suction velocity
RE: Maximum suction velocity
Each pumping unit can pump 33,000 gpm. Each pump has its own individual suction pipe (14 ft in length) out of the wet well. There are no suction headers.