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bjhaffly · Aug 20, 2009, 04:33 PM

I have a ten year old well 240' deep with a Franklin submersible pump. It has a Well Rite 140 OLC pressure tank and a Square D pressure switch. 250' to house, 125' of 1' then 125' of 3/4". It averages 8 GPM; pressure gauge reads 30lb when pump is on. Pressure has always fluctuated with poor pressure at the house.

Pump will run out of water if you run it for more than 30 minutes. Water is undrinkable, leaves buildup on all faucets, shower heads, toilets etc. Hot water heater, washer and dishwasher average 3 years before replacement.

I now have the budget to upgrade the system but, not the budget to pay to have it done. I plan to install a 550 gallon holding tank and reduce the flow to the tank in hopes of not running the well out of water. Then install a jet pump to increase the house pressure and hopefully stop the fluctuating pressures. I have spoken to two plumbing suppliers and have two different ideas on how to set it up.

I made a drawing of the last guy's idea but I'm not sure if I got everything laid out the way he explained it to me or if all the accessories are correct and in the right places.

A couple things I'm not sure of:
He said I would need an UP float valve and a DOWN float valve?
I'm assuming the pressure switch at the submersible pump controls it. What turns on the Jet Pump or is there a certain type of jet pump required?

http://eepurl.com/c9vg

Any help anyone can give me would be greatly appreciated.
BJ

Scleros · Aug 20, 2009, 07:08 PM

I was looking at building a similar arrangement for my low pressure situation due to a chicken processing plant near me on the same city water line. Similar to your diagram what I envisioned would have required an upper and lower limit switch (float) for the control circuit to turn the well pump on and off that feeds the holding tank. A pressure switch then controls the other pump that feeds the small pressure tank like in a traditional well setup. While trying to sort out all the design details in my head I caught a ThisOldHouse episode one afternoon and saw them install an already engineered and packaged pressure booster device (examples: Towle-Whitney, PressureBooster.com) and decided to go that route rather than cobble something together myself and have to deal with the local plumbing inspector. You could probably talk to one of the pressure booster manufacturers and have them customize one for use with a holding tank, supply one with a larger pressure tank, or some variation to fit your needs.

jlisenbe · Aug 20, 2009, 08:12 PM

The float valve will control the submersible pump.

The pressure switch will control the booster pump.

An UP float valve would, I suppose, be one which turns OFF in the uppermost position.

If it was me, I would the booster pump pumping into the WelRite pressure tank.

How do you intend to reduce the flow of the submersible pump to the holding tank? If anything, since it will no longer have to pump against the pressure of the tank, the pump volume will increase. That will prove to be a problem for you if the well tends to run out of water if pushed too hard.

hkstroud · Aug 21, 2009, 05:17 AM

You said, "It averages 8 GPM;"
Is that at the wellhead or at the house?

You said " pressure gauge reads 30lb when pump is on."
OK, that is the cut in pressure. What is the cut off pressure?

You said "well 240' deep"

Do you know that the pump is at the bottom of the well?
Do you know the pump size?

You said, " Water is undrinkable"
Why? Sand, mineral deposits, sulfur, iron?

Your existing 140-pressure tank should give you about 50 gallons storage of useable water when pressure is set to 40-60. An additional 550-gallon tank would give you a total of about 250 gallons. How much water do you need?

jlisenbe · Aug 21, 2009, 05:22 AM

Bear in mind that the 550 gallon tank is storage only... it is not a pressure tank. I would think it would be good for at least 450 gallons, allowing for a little empty headspace.

I think his basic idea is sound. It will allow him to spread his water demand over a much longer period, even pumping some, possibly, at periods during the night, so as not to pump the well dry. He says his pump is only good for thirty minutes and then it runs out of water. The trick will be this. With that large of a storage tank, when the float valve comes on, it will be looking for a LOT of water before it cuts off. Your thirty minute problem will still be there. You will need to shorten pump cycles somehow. That, to me, will be the challenge.

hkstroud · Aug 21, 2009, 09:17 PM

I agree, seems to me that you would have to have some kind of timer.

He said that he has 8 GPM but I suspect that is out the tank under pressure. If he has 8 GPM at the wellhead, I don't think he would be complaining. I suspect that well and pump capacity is much lower.

A well, producing 2 GPM, and a 140 gallon pressure tank should give you about 100 gallons available during a 30 minute period.

The complaints about pressure variations make me wonder about the cut off setting of the pump.

I would think the first thing to do would be check the capacity of the well and pump.

Would also like to know the size of the pump. Perhaps a larger pump or a booster pump is the answer.

If I were attempting to set this system up, I think I would set the 550 tank up as a pressure tank, fed by the 140 tank, and metered such that the pump has a chance to shut down. For instance if the well can produce 2 GPM and the flow between tanks is restricted to 1 GPM, the pump should run about 50% of the time until both tanks are at capacity. That 500 tank should probably be a bladder tank about 60-80 gallons.

As a final thought, I wonder is the well is really being temporarily depleted or if it's just a drop to flow and pressure of the well it self.

Just my thoughts, certianly like to hear yours.

KISS · Aug 21, 2009, 09:37 PM

You also need to consider a water treatment system (water softener?). Get your water tested and then see what you need. Iron requires a little more help.

30 minutes of water isn't all that bad. I might change priorites and get the water treated first.

jlisenbe · Aug 22, 2009, 06:59 AM

Hold everything. I would not set the holding tank up as a pressure tank unless it IS a pressure tank. Many holding tanks are simple plastic or fiberglass tanks and are not designed to operate under anything more than nominal pressure. I'd be willing to bet the 550 gallon tank is not a pressure tank. If it is, I'd hate to see how much he had to pay for it.

On the other hand, HK's comments about the pump's capacity are worth reading. I would think he is right on the money.

hkstroud · Aug 22, 2009, 07:19 AM

"bet the 550 gallon tank is not a pressure tank"

I'll go along with that. I guess I was thinking in terms of a large pressure tank. My error, another reason that the approach didn't seem practical.