# pressure tank vs constant pressure systems



## Dairylander (Oct 27, 2009)

I can't find a good comparison between these two options.
It's a duplex with one well serving 2 kitchens and 3 baths.
The veterans at the Ridgid forum said that constant pressure is "unnecessarily complicated & expensive."
But my subcontractors are telling me that 80% of what they are installing is constant pressure.
Any help explaining this?
Thanks.


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## PPRI (Oct 9, 2010)

When most people refer to a constant pressure system, they are talking about a variable rate submersible pump. This system has served us well over the years. A standard submersible pump has either off or on. The pump will put out a set gpm at a certain psi dependent on the lift distance. The pressure switch turns on the pump, it runs full blast till the pressure switch turns it off. The pressure tank is used to absorb some of the pressure given off by the pump and uses it as a buffer between the time you turn on a fixture and the pump kicks on. 

A variable rate pump is very similar and is usually paired with a small 6 gallon pressure/expansion tank. The difference is that to pump will run only enough to match the load from a fixture or fixtures. This eliminates pressure spikes and drops when running a fixture at a low gpm. A variable rate pump is more expensive but we have found that they break down less often. We believe it's because they don't short cycle as much when used in residential applications.


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## Oconomowoc (Oct 13, 2011)

Dairylander said:


> I can't find a good comparison between these two options.
> It's a duplex with one well serving 2 kitchens and 3 baths.
> The veterans at the Ridgid forum said that constant pressure is "unnecessarily complicated & expensive."
> But my subcontractors are telling me that 80% of what they are installing is constant pressure.
> ...


The plumbers on the Ridgid forum are correct. A duplex is all about ROI, so when you compare the two what is the result? You get a better ROI with a standard pressure tank. Spending extra money somehow needs to be justified on investments. What is the advantage over a standard PT that obviously works very well? Nothing.

If the PT goes bad so what, it's cheap and can be changed out in less than an hour. What's not to like about that?


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## Oconomowoc (Oct 13, 2011)

PPRI said:


> When most people refer to a constant pressure system, they are talking about a variable rate submersible pump. This system has served us well over the years. A standard submersible pump has either off or on. The pump will put out a set gpm at a certain psi dependent on the lift distance. The pressure switch turns on the pump, it runs full blast till the pressure switch turns it off. The pressure tank is used to absorb some of the pressure given off by the pump and uses it as a buffer between the time you turn on a fixture and the pump kicks on.
> 
> A variable rate pump is very similar and is usually paired with a small 6 gallon pressure/expansion tank. The difference is that to pump will run only enough to match the load from a fixture or fixtures. This eliminates pressure spikes and drops when running a fixture at a low gpm. A variable rate pump is more expensive but we have found that they break down less often. We believe it's because they don't short cycle as much when used in residential applications.


Really? I change pumps all the time. A standard pump lasts a hellofa long time and it's cheap.


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## PPRI (Oct 9, 2010)

Mike, I'm not going to argue that a standard pump and pressure tank is cheap, rugged and dependable. That is still the bulk of well systems. The op didn't sound lime he understood the systems so I thought I'd throw a couple pennies at it. I know a lot of people who get irritated with the small pressure spikes of a standard pump/tank system. I'll more than gladly give them a variablerate in those situations. Get off C.T. and get to work on those racks.


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## Oconomowoc (Oct 13, 2011)

Screw the racks. I'm teaching my daughter how to be a rebel.


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## PPRI (Oct 9, 2010)

Please tell me she's actually mowing. You my friend get my father of the year award. I felt kinda bad. I busted azz putting up fence all afternoon instead of spending time with the kids. Of course it was fence for their goat herd though. Being a dad can be a thankless job until those special moments like watching your daughter wake board behind the lawnmower as she mows the back yard.


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## KillerToiletSpider (May 27, 2007)

I have that same Snapper tractor.


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## Oconomowoc (Oct 13, 2011)

KillerToiletSpider said:


> I have that same Snapper tractor.


I just love my Snapper


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## Dairylander (Oct 27, 2009)

Thanks guys.
Looks like I'll stick with the standard pressure tank.
Do I need a cycle stop valve?


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