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Robbies

Senior Member

Posts: 32

Location: USA

1

Tuesday, April 19th 2005, 9:32am

GPM question

Ok I have 12gpm and pump turns on at 40psi and off at 50.

That means that every zone must have 12gpm. Otherwise the pump turns on and off and that is not good for it. Is this correct?

If I use 8gpm of that 12 the pump turns on and off and the pressure changes from 50 to 40. I have all rotor zones that use all 12gpm .

I dont have a problem just wondering on the issue as i read people saying stuff about being under?

You must use all the gpm or you wont have a constant pressure right?? WHat is another solution to keep constant pressure??

Robbies

Senior Member

Posts: 32

Location: USA

2

Tuesday, April 19th 2005, 9:32am

GPM question

Ok I have 12gpm and pump turns on at 40psi and off at 50.

That means that every zone must have 12gpm. Otherwise the pump turns on and off and that is not good for it. Is this correct?

If I use 8gpm of that 12 the pump turns on and off and the pressure changes from 50 to 40. I have all rotor zones that use all 12gpm .

I dont have a problem just wondering on the issue as i read people saying stuff about being under?

You must use all the gpm or you wont have a constant pressure right?? WHat is another solution to keep constant pressure??

drpete3

Supreme Member

Posts: 376

Location: USA

3

Tuesday, April 19th 2005, 11:41am

first the pump may not be able to reach the 50 psi to turn it off running at 8 gpm. What I mean is if you turn on your 8 gpm zone the pressure will drop to 40 then the pump will kick on. At this point it will work its way back up to 50 psi but it may never reach that point. It may lvel out at 47 psi and run at that pressure.
Thanks,

Pete

Robbies

Senior Member

Posts: 32

Location: USA

4

Tuesday, April 19th 2005, 12:46pm

But on my system right now it is 12gpm zones and it goes down to 40 and turns on it then levels out to about 45-48psi.

Robbies

Senior Member

Posts: 32

Location: USA

5

Tuesday, April 19th 2005, 2:33pm

I recorrect myself the pump turns off at 50 and on at 30 psi then works it way to about 42-44psi

for the 1 zone that has 10.5 gpm it comes up to 48 psi and stops.

drpete3

Supreme Member

Posts: 376

Location: USA

6

Thursday, April 21st 2005, 5:35am

So there is no other way to achieve a constant pressure. You need to design your zones around your pump.
Thanks,

Pete

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