Flow rates

[tcat]

I have a new Pentair Superflo VS (1.5hp), run it 2950-1.5hrs, 1350-10hrs, 2750-1.5hrs. I have a Gulfstream he110 heat pump that shuts off on low for of 30gpm.

Anyone have an estimate of flow rate at 1350? I have not cranked it down yet to see when the HP shuts off, but I'm guessing 1350 must be close (like maybe 35 gpm?)

 

[mas985]

It depends on your plumbing layout. It will most likely be between 25-30 GPM. But to get a better estimate, I would need the following:

Filter pressure on full speed
Height of the filter gauge relative to water level.
Length of suction lines pool to pump
Suction pipe diameter
Number of suction lines from pool to pump

 

[tcat]

It depends on your plumbing layout. It will most likely be between 25-30 GPM. But to get a better estimate, I would need the following:

Filter pressure on full speed
Height of the filter gauge relative to water level.
Length of suction lines pool to pump
Suction pipe diameter
Number of suction lines from pool to pump

Filter pressure on full speed
18psi (3000rpm)
Height of the filter gauge relative to water level.
2.5' to pump, +3.5' to gauge (top of filter)
Length of suction lines pool to pump
60' to skimmer
75' to bottom drains (2)
Suction pipe diameter
2"
Number of suction lines from pool to pump
2 (probably 4 elbows on each)

Thanks!

 

[mas985]

1350 RPM would be about 22 GPM.

For any RPM:

Flow Rate (GPM) = 50 * RPM / 3000

Your system seems to have a lot of head loss for 2" plumbing. The HP is probably contributing to some of that. Has the filter pressure always been that high?

[EDIT] Updated. Used wrong pump. Do you have the VS 342001?

 

[tcat]

Yes 342001. I haven't backwashed the filter in a couple months, but with my old 2 speed pump a clean filter would start at about 20psi.

 

[mas985]

BTW, most heaters work on pressure and not flow rate so that may be why you can operate at a lower GPM. The pressure is still sufficient for the pressure switch in the heater.