Estimated flow?

[MartinM]

I’ll be reducing a Vectra L2 from 1.25” (32mm) to 20mm (3/4”). There will be about 200cm of vertical head and about 100cm of horizontal run. Any guesstimates on actual flow rate at max power?

 

[P-Dub]

Estimate, and an estimate only... roughly 1100-1500 depending on the number of elbows. Easiest is to measure the time it takes to fill a particular volume of water. i.e. 1-gallon container takes x number of minutes/seconds to fill...

 

[DCR]

I size lines and pumps professionally as an engineer and I would not expect to get much more than 400 gph through a 3/4" line without very large friction losses. It really makes no sense to use 3/4" with an L2. You are wasting a lot of power. Not sure how much flow you are looking for but you need to either increase the pipe size or maybe consider a smaller pump. I would use 1" up to about 600-700 gph, 1-1/4" up to about 900-1000 gph, 1-1/2" up to about 1800 gph and then 2" above that up to about 3000 gph.

 

[ca1ore]

Not a professional engineer, but a professional pessimist ..... I'm in the 500 GPH range too! Don't know what that is in LPH.