What PSI should be in my well expansion tank?

[plowhog]

when I had a low flow shower head, it took me at least twice as long to shower, so that didn't work out!..

Not to mention the toilets that use half the water but need flushing three times!

 

[Oldoak]

30/50 should be liked because the pump turns on fewer times for your examples....but takes longer to complete them.

I disagree. 30/50 or 40/60, both being a 20# differential, the pump will turn on the same amount of times.

 

[radios1]

Not to mention the toilets that use half the water but need flushing three times!

the water conservation is only for reducing the GPH needed at the pump station.. the same gallons are used, but at a slower rate(smaller pump can be used)..

 

[Clint S]

I disagree. 30/50 or 40/60, both being a 20# differential, the pump will turn on the same amount of times.

Nope, there are more variables than pressure when it comes to the pump running. There is less drawdown water volume available in a tank as you increase the air pressure in the bladder. With the increased air in the bladder the draw down gallons will be less and the pump will run more. A 20 gallon tank will hold approximately 1 gallon less at 40/60 than 30\50. Your pump also has to work a little harder to push water at higher pressures.

 

[Valveman]

No I did not drain the tank. Much to learn!!

Your bladder or diaphragm in the tank is most likely bad. They usually don't lose the air charge until the bladder is broken. Adding air maybe a temporary fix, but sometimes the broken bladder seals over the inlet/outlet hole and the tank won't work at all. Turn off the pump, open a faucet until the pressure gauge reads zero, leave the faucet open and add air to the tank. If air comes out the faucet the tank is bad. Like has been said, tank needs 2-5 PSI less air charge than the pressure switch start pressure.

Most switches are either 30/50 or 40/60. Ours is 30/50, which I like because it uses less water. Being on a well using less water is important and we really don't notice any difference.

40/60 is more common these days. And actually the pump produces more water at 30/50 that at 40/60, which makes the cycling worse. As has been said your washing machine, dishwasher, tub, and other things will still use the same amount of water, they just take longer to fill up. Your shower and sinks will put out less flow at the lower pressure, but then you just have to take longer showers to get the soap rinsed off. Quicker showers at higher pressure may even use less water than slower showers at lower pressure. 40/60 gives and average of 50 PSI and will make the shower pressure stronger than 30/50. But a constant 50 PSI, using a constant pressure type system will give even stronger shower pressure than an average 50 PSI.

I am always irritated with well owners who complain about low pressure and WISH they had strong "city like" pressure. It is your pump system. You can have as much pressure as you want. You just have to make it happen. My city dwelling friends love the strong constant shower pressure at my house and WISH their city pressure was as good.

Rapid cycling like you described is a serious problem and kills pump motors in a short time and as mentioned earlier you may have a pressure tank failure.

Rapid cycling that happens with a bad tank will certainly destroy a pump quickly. However, what some would call "normal cycling" is what causes the bladder in the tank and many other things to fail to start with. Every time the pump cycles on/off the bladder in the tank goes up and down like bending a wire until it is broken. Then the broken bladder causes "rapid cycling" and the entire system will be destroyed very soon. So even "normal cycling" is what eventually destroys all pump systems.

Right. In fact a bladder with holes works fine IF you had a way to replenish the air that slowly dissolves into the water over time (days/weeks).
My momç—´ tank has no bladder, but it does have a air volume control (ACV) valve that replenishes dissolved air.

Many times a piece of the broken bladder will plug the inlet/outlet hole and water cannot get in or out of the tank. Even if it works the water on the top side of the bladder will get old and slimy and can contaminate the other water in the tank.

An AVC on a standard air over water tank lets the excess air out. The bleeder orifice/check valve/schrader valve set up is what lets the air in the tank.

30/50 should be liked because the pump turns on fewer times for your examples....but takes longer to complete them.

Again a pump will produce more water at lower pressure, so the cycling will actually be more at 30/50 than at 40/60.

Things like showering, hand washing, teeth-brushing will take less water at lower pressure because the fixture will have a lower flow. Things that take a constant amount of water -- toilet flushing, dishwasher, washing machine -- will still use the same amount, they just might take a little longer.

Exactly right! But I find that even showering uses the same amount of water as it takes longer to shower at the lower pressure.


Yes there is less draw down in a tank at 40/60 than at 30/50, but the increased flow from the pump at low pressure is what causes quicker cycles. I agree with the low flow toilets needing to be flushed 3 times. LOL And again, showers take longer at low pressure, requiring more time, but using the same amount of water.

 

[CobyRupert]

Adding air maybe a temporary fix, but sometimes the broken bladder seals over the inlet/outlet hole and the tank won't work at all. Turn off the pump, open a faucet until the pressure gauge reads zero, leave the faucet open and add air to the tank. If air comes out the faucet the tank is bad. Like has been said, tank needs 2-5 PSI less air charge than the pressure switch start pressure. -Good diagnosis trick.

40/60 is more common these days. And actually the pump produces more water at 30/50 that at 40/60, which makes the cycling worse. Agree that 30/50 pump produces more water. It also runs at lighter load (better temps and less amps), and runs for shorter amount of time per cycle. And seeing how the drawn down is more (more gallons per cycle) as you state below, this makes for better cycling.

Many times a piece of the broken bladder will plug the inlet/outlet hole and water cannot get in or out of the tank. Even if it works the water on the top side of the bladder will get old and slimy and can contaminate the other water in the tank. -Good point

An AVC on a standard air over water tank lets the excess air out. The bleeder orifice/check valve/schrader valve set up is what lets the air in the tank. No. The AVC I'm familiar with sends a gulp of air into tank every time pump starts. It's required on an air over water tank to make up for for the air in the tank this is lost/dissolved into the water over time.

Again a pump will produce more water at lower pressure, so the cycling will actually be more at 30/50 than at 40/60. The cycling of the pump will be more dependent on how many gallons of water the ballast tank gives up between its cut-out and cut-in pressures, when the pump is not running. As you note below, the drawn down on 30/50 is greater.

Yes there is less draw down in a tank at 40/60 than at 30/50, but the increased flow from the pump at low pressure is what causes quicker cycles. It may effect pump run time, but not quicker cycles. Cycles are longer because more water can be drawn down before pump needs to turn on again (not to mention it takes longer to get that extra water out at lower pressure too).

:2cents:

 

[Valveman]

Agree that 30/50 pump produces more water. It also runs at lighter load (better temps and less amps), and runs for shorter amount of time per cycle. And seeing how the drawn down is more (more gallons per cycle) as you state below, this makes for better cycling.

Actually no. Lower pressure means the pump is producing more GPM, which makes it draw more amps and run hotter. Increasing the operating pressure makes the pump produce less flow. Pumps are counter intuitive. Restricting the flow or working at higher pressure makes the pump work easier, draw lower amps, and run cooler. Running wide open at high flow and low pressure will make the pump/motor draw higher amps, produce more heat, and work harder.

Tank draw down maybe higher at low pressure, but the amount the pump produces increases more than the drawdown increases. Increasing the shut off pressure close to the max pressure the pump can build will reduce the flow from the pump and reduce pump cycling. Increasing the pressure will also make the pump run cooler and last longer. Just the opposite of what most people think about pumps. Like i said they are counter intuitive.

No. The AVC I'm familiar with sends a gulp of air into tank every time pump starts. This compensates for the air in the tank this is lost/dissolved into the water over time.

An AVC on a jet pump will add a gulp of air. The AVC on a submersible pump relieves excess air from the tank that was added with the bleeder orifice and schrader valve.

 

[radios1]

Actually no. Lower pressure means the pump is producing more GPM, which makes it draw more amps and run hotter. Increasing the operating pressure makes the pump produce less flow. Pumps are counter intuitive. Restricting the flow or working at higher pressure makes the pump work easier, draw lower amps, and run cooler. Running wide open at high flow and low pressure will make the pump/motor draw higher amps, produce more heat, and work harder.

Tank draw down maybe higher at low pressure, but the amount the pump produces increases more than the drawdown increases. Increasing the shut off pressure close to the max pressure the pump can build will reduce the flow from the pump and reduce pump cycling. Increasing the pressure will also make the pump run cooler and last longer. Just the opposite of what most people think about pumps. Like i said they are counter intuitive.

just like an HVAC blower..

 

[Valveman]

just like an HVAC blower..

Yes!!

 

[Langanobob]

Valveman, thanks for your post. I was going to say the same thing, got down to the end of the thread and you already said it a and better than I would have.

One concern I have about my well pump, which is set deep due to declining water table is the wear on the thrust beating. Granted it cycles less and is under less electrical load but I think there may be a tradeoff with thrust bearing life.