Well Tank Replacement/size

[Vincent McMahon]

Hi there, I just learned that my well tank bladder is leaking. When I pump air into the tank bladder, it comes out of the drain valve. I topped it up to 38 IBS and refilled the tank for now. I need to replace it. It's a 2008, Amtrol Water Pro WP44, 100 PSI max working Pressure. I am assuming that's 44 Gallons? I have a 1/2 HP, 7 GPM Submersible. What is the best replacement tank make/model to go with in this day, and is there any advantage of going with a larger tank? We are a 5 person household. I like/want high-pressure to our showers, and we have a high-volume shower that is just being completed at the moment also, so if a bigger tank is more beneficial, I would consider upgrading. If it makes no difference, then I can go with a similar size. appreciate any advice on size and best make to go with. thanks everyone

 

[Reach4]

A 44 gallon tank will hold about 11 gallons of water. A 7 gpm pump will usually draw about 8 gpm. Eleven is more than 8, so the run time should be over a minute. So that is a good size.

WX-250 is the same size, but is the higher-end Amtrol brand.

An alternative is to use a CSV with a smaller tank.

Custom PK1A PSIDE-KICK Pressure Tank Kit

Replaces large pressure tanks. Preset and easy to install for the DIY customer. The pside-kick kit is a complete constant pressure control package for most pump systems with demands from 1 to 25 gpm. This kit comes with everything you see and utilizes a mechanical pressure switch.

cyclestopvalves.com

 

[Sponsor]

 

[Vincent McMahon]

Thanks @Reach4 . Would The CSV give me any other benefits? Would I have more constant pressure? I am ok installing the tank, is the CSV much additional in terms of complexity?

 

[Bannerman]

The water you use, is delivered by the well pump. The well pump repeatedly cycling On & Off while water is being used, is why your pressure tank diaphragm wore out prematurely, just as will also reduce the usable lifespan of the pressure switch and pump.

Utilizing a Cycle Stop Valve will cause the well pump to supply only the exact amount of water that is being utilized at the time. Since the CSV will prevent pump cycling, the well components mentioned will undergo far less wear and tear.

Additional benefits for a CSV include constant water pressure provided to your home's plumbing fixtures and appliances, the ability to utilize a much smaller and less costly pressure tank, and less pressure variance while showering at the same time a toilet is flushed or the dishwasher or clothes washer is running and filling with water.

To better understand how a CSV functions compared to a common pressure tank setup, see the interactive demo linked below.

CSV Interactive Demo

 

[Vincent McMahon]

Thanks for that detail. Playing devil's advocate, is there any downside to this system? Looks like a smaller system, which I could use, and pressure variations drive me nuts so that's a plus.

I hear your point about preventing the pump from cycling on and off, but given the pump is 18 years old, does that still hold true? It's a 1/2 HP gould Submersible 7 GMP. (What is the life of one of these pumps?)

Are there any reliable resources that I can call to help me design how this would look, so I can order all the parts for my particular setup? ( I hope I am not opening up a ton of sales messages here...lol)

thanks all fo your help..

 

[Valveman]

The average life of any pump is 7 years. You have been on borrowed time for quite a while. A 1/2HP will take more abuse (cycling) than larger pumps, but cycling is still the most likely cause of failure. The CSV cannot undo the 18 years of abuse, cut can prevent anymore from happening. The only thing a pressure tank does is reduce the on/off cycles. When you have a Cycle Stop Valve to do that for you a large tank is a waste of space and money. Also, the smaller the tank the less pressure variation you will have before the CSV takes control and delivers strong constant pressure to the house. The only downside to the CSV is that you haven't had one for the last 18 years as they have been available for over 30 years.

 

[Vincent McMahon]

@Valveman @Reach4 @Bannerman

Thanks for your responses. I have been looking at the interactive demo. Mechanically, how exactly does this valve work? From the demo, it does not allow the attached tank to fill while there is a drawdown. Does it divert water away from the tank to maintain the constant flow?

If my old submersible is pumping 7 GPM, against say 50 PSI valve and a shower using 1-2 GPM, does this not put pressure on the downstream side of the CSV, and the pump? In the traditional setup, the pressure switch would shut off the pump right?
Will this be an issue? Not sure how all this works?

Are there dealers that install these? I talked to my well guy and he does not know anything about these.

 

[Reach4]

The CSV limits the flow to about 1 GPM if the pressure is above the setpoint. So with a 40/60 PSI pressure switch, and CSV adjusted to 50, the pressure tank fills quickly to 50 psi but the water usage is also drawing water. If more than 1 gpm of flow is being used, the presure levels at 50 psi. When you stop using water, the tank slowly fills from 51 to switch cutoff.

Pressure switch still starts and stops the pump.

There is increased backpressure out of the pump when pressure out of the CSV is getting over 50 psi. Piping would normally not have a problem with that. Surprisingly, the electrical current to the centrifugal pump decreases when the backpressure increases.

 

[Valveman]

@Valveman @Reach4 @Bannerman

Thanks for your responses. I have been looking at the interactive demo. Mechanically, how exactly does this valve work? From the demo, it does not allow the attached tank to fill while there is a drawdown. Does it divert water away from the tank to maintain the constant flow?

If my old submersible is pumping 7 GPM, against say 50 PSI valve and a shower using 1-2 GPM, does this not put pressure on the downstream side of the CSV, and the pump? In the traditional setup, the pressure switch would shut off the pump right?
Will this be an issue? Not sure how all this works?

Are there dealers that install these? I talked to my well guy and he does not know anything about these.

Just a simple spring operated valve. When adjusted to 50 PSI the spring pushes the valve open anytime there is less than 50 PSI. When the water pressure is higher than 50 a diaphragm pushes back to close the valve, delivering less water. Basically it opens or closes as needed to keep the pressure at 50 all the time. When no one is using water, a simple 1 GPM hole or bypass lets the tank fill to 60 PSI so the regular pressure switch can shut it off.

Pump supply houses have been trying to keep the CSV a secret from pump guys for over 30 years because they are inexpensive, last a long time, make the pump last a long time, and work with a much smaller tank. They rather he sell something expensive that doesn't last long like a VFD. I'll bet he knows what that is. I can talk him through it or any plumber can do it after the pump man leaves.

 

[Vincent McMahon]

Thanks for your detailed information. @Valveman, So I am clear, when a draw is happening, it allows more than 1 GPM through, say to a shower, or filling a tub. But it only throttles to 1 GMP when filling the pressure thank backup?

I am still not overly clear on the impact on the submersible pump when it's pumping at 7 GPM, against the CSV, and say a shower is drawing only 2 GPM. Does this not cause backup pressure against the pump, or are they smart enough to slow down? or does it fill the tank and the pressure switch shuts it off? I don't know much about how pumps work from this point of view. I just fear that if it is pumping 7 GPM and only 2 being drawn, with the smaller tank will it cycle off/on a lot, or cause backup pressure against the pump.

 

[Valveman]

The CSV is such a simple valve it is hard to explain or understand. The CSV is just a spring operated valve with no electrical connection. It cannot do anything until the pump comes on. Once the tank is empty and the 40/60 pressure switch sees 40 PSI the pump is started. When the tank is filled to 50 PSI, which is also the setting of the CSV, the CSV starts regulating the pressure to maintain 50 PSI. If more taps are opened and the pressure drops to 49 PSI the 50 PSI spring in the CSV pushes the valve open to deliver the extra water needed. When a tap is turned off, the pressure climbs to 51 and the diaphragm on the other end of the spring is now stronger than the spring and pushes the valve closed to deliver less water as needed. Basically, once the pump is started, the CSV works as a pressure regulator to maintain 50 PSI constant, and keep the pump running continuously, no matter how much or how little water is being used. Without a CSV the pump would just destructively cycle on and off from 40 to 60 over and over as long as any water is being used. When all taps are closed, the CSV just cannot close to less than 1 GPM (simple hole or notch on the valve seat), Then at 1 GPM rate the pressure tank will be filled from 50 PSI to 60 PSI where the pressure switch will shut the pump off. Really simple. Hard to explain or understand. Maybe this will help. But the CSV does not slow the motor down and the pump will not turn off during a shower, even if the shower is on for a month.

 

[Vincent McMahon]

@Valveman . This is very helpful overall. I am just not getting what happens when the pump is lifting 7 GPM from the well, but the house is only drawing 2 gpm for say, a shower. There is a 5 GPM difference. You're saying that as long the shower is running, the pump will run, but if the pump cannot throttle down - will this not kill the pump? Where does this extra water do? I admit I am not an expert in pumps, just try to wrap my head around this

 

[LLigetfa]

I am just not getting what happens when the pump is lifting 7 GPM from the well, but the house is only drawing 2 gpm for say, a shower. There is a 5 GPM difference.

In that scenario the pump is only lifting 2 GPM from the well so there is not a 5 GPM difference.

 

[Valveman]

I know right? Like I said, it is so simple it is hard to understand. The CSV works the same as any ball valve, it just opens and closes. It is just spring controlled instead of having a handle on it. Less than 50 PSI pressure in the house opens the CSV and more than 50 PSI closes it.

When you valve back on a pump, it makes the pump think the well is deeper. That is a 7 GPM pump because 7 GPM is the optimal flow for that particular size impeller. But, it will pump 1 GPM in a 410' deep well, 7 GPM when lifting from 280' deep, and 9 GPM if the water in the well is only 180' deep. With the understanding that 115' of that total head is needed to make the 50 PSI pressure needed at the house, you can size the pump as needed for the depth of water in the well.

A 3/4HP, 7 GPM pump will produce 7 GPM at 50 PSI at the house while pumping from a depth of 165'. When the CSV makes the pump produce only 1 GPM as is needed for a sink at the house, the CSV holds back water until the pump thinks the well level has dropped to 295', even though your well is not that deep. The well could only be 10' deep with a water level of 1' from the surface and the pump still thinks it is lifting from 410' when needed. See the performance pump curve attached.

OK, now if you understand that your next question is going to be, "What happens to a pump in a 10' deep well when it is being restricted to think the well is 400' deep? Isn't that going to make the pump work much harder?" No. Just the opposite is true. That is the part that is hard for our brains to understand. It is completely counter intuitive, just the opposite of what our brains want to think. Some peoples minds are just never able to accept it. Lol! Restricting a centrifugal impeller pump with a simple valve makes the amp draw/watts used decrease, not increase. See the power section of the curve supplied to see this pump uses 1.1HP to pump 9 GPM when it thinks the well is shallow, and only 0.6HP pumping 1 GPM when it thinks the well is deep.

If the well is only 10' deep, that would cause there to be 177 PSI on the inlet side of the CSV while it is supplying 1 GPM at a constant 50 PSI on the other side of the CSV to the house. The deeper it is to water the less pressure on the inlet side of the CSV by 1 PSI for every 2.31'.

 

[Valveman]

In that scenario the pump is only lifting 2 GPM from the well so there is not a 5 GPM difference.

Yeah, there is no water left to circulate, dump, or anything. But that is a very common question. Most people think a 7 GPM pump always pumps 7 GPM and don't realize that 7 GPM is just optimal and it will work anywhere on the curve from zero to max flow.