Well pumps, aerators, & pressure tanks

[Marine67]

I have an above ground well pump, pumping water into an aerator, which has a float valve controlling the pump. The pump is also attached to the pressure tank. I cannot understand why the pressure tank in this situation. Water pressure is not the controlling factor with my well pump. Tge float valve is, I think. Any thoughts on the need of a pressure tank in this set up?

 

[Valveman]

If you had a float switch, no pressure tank would be needed. But with a Float valve, the pressure tank is needed because the pressure switch is what turns the pump on and off.

 

[Sponsor]

 

[Marine67]

If you had a float switch, no pressure tank would be needed. But with a Float valve, the pressure tank is needed because the pressure switch is what turns the pump on and off.

The float in my aerator is what turned on the well pump. When the water fell in the aerator, and the float fell below level, the water pump would kick on. When the float was pointing above level, the pump would turn off. I still have the float in my aerator, so I am confused why I have a pressure tank. The float still controls the pump, but I’m not sure how the pressure turns on the pump. No additional electrical was installed. And what pressure is the pressure tank monitoring?

 

[Bannerman]

In your initial post, you said a float 'VALVE' turns on the pump.

If a float valve is utilized, the valve will open when the water level is low in the aerator so as to cause pressurized water from the pressure tank to enter the aerator. This will in turn cause the system pressure from the pressure tank to become gradually lower, thereby causing the pressure switch to activate the pump when the system pressure has fallen to the PS activation setting.

If you actually mean a Float 'SWITCH' is utilized, then low water level in the aerator will cause the float to activate a switch which will directly activate the pump. When a float switch is utilized, a pressure tank and pressure switch will not be required.

The float still controls the pump, but I’m not sure how the pressure turns on the pump. No additional electrical was installed. And what pressure is the pressure tank monitoring?

A pressure tank supplies system pressure while the pump is not running. The pressure switch monitors the system pressure so as to activate the pump when the system pressure has been reduced to a specific pressure, and will shut off the pump when the system pressure has been increased to typically 20 psi higher that the activation pressure.

 

[Marine67]

In your initial post, you said a float 'VALVE' turns on the pump.

If a float valve is utilized, the valve will open when the water level is low in the aerator so as to cause pressurized water from the pressure tank to enter the aerator. This will in turn cause the system pressure from the pressure tank to become gradually lower, thereby causing the pressure switch to activate the pump when the system pressure has fallen to the PS activation setting.

If you actually mean a Float 'SWITCH' is utilized, then low water level in the aerator will cause the float to activate a switch which will directly activate the pump. When a float switch is utilized, a pressure tank and pressure switch will not be required.



A pressure tank supplies system pressure while the pump is not running. The pressure switch monitors the system pressure so as to activate the pump when the system pressure has been reduced to a specific pressure, and will shut off the pump when the system pressure has been increased to typically 20 psi higher that the activation pressure.

There is, or was, no pressure on the aerator. The well pump turns on when the water level falls. Then the water is pumped directly into the aerator until the required water level is once again reached. The switch in my aerator is a float. Level down, pump starts, when water rises above level, pump stops. Well pump is on one side of aerator, and the pump for water to the house, also attached to a pressure tank is pressure controlled. It’s set to 30/50. When we run water in the house, the pump kicks in when pressure falls to 30psi and turns off at 50psi. The pressure tank attached to the well pump, has no settings. There is no pressure gauge attached to well pump pressure tank.

 

[Valveman]

Again, if you have a float switch, not a float valve, no pressure tank is needed.

 

[Marine67]

Again, if you have a float switch, not a float valve, no pressure tank is needed.

Ok, I think I shouldn’t have agreed to another pressure tank. Thanks for your patience, and I appreciate your help in helping me to understand the workings of pumps with aerators.

 

[jbeech]

I think Marine67 and Valveman experienced a failure to communicate, and the next guy to trip across this thread may be confused.

Aerator tanks have a toilet valve like mechanism to shut off the water flow through spray nozzles used to fill the holding tank. Once this valve closes, pressure in the system builds. The pump supplying water is equipped with a pressure switch and a pressure tank.

The purpose of this combination is to allow water under pressure to flow from the pressure tank without turning on the pump. If you don't have one of these, then every time you turn on the water, the pump would come on, which would greatly shorten the working life of the electric motor.

However, where I think the failure to communicate entered into things is Marine67 believes the mechanical float valve is what controls the pump. It doesn't, it just controls the build up of pressure.

So it's the actual float valve shutting off the flow of water, thus allowing pressure to build (obviously, because when the valve is open, then in effect the system has a leak). And it's the build up in pressure with the valve closed, which is what the pressure-switch equipped pump uses to turn on and off).

So it seems like cause and effect - and it is - but it's indirectly.

And it does not function in the same way as a water-level switch (a direct method of turning the pump off and on). This works because there's an electric device - a switch - mounted within the aerator tank. The direct water level switch must have a wired electrical connection between the float mechanism within the tank, and the pump. No electrical connection, then what turns the pump on and off is a mechanical valve controlling flow and thus, pressure, instead.

So one method, the toilet valve, shuts off the water as the float rises thus allowing pressure to build and the pump equipped with a pressure switch (and pressurized holding tank) turns off. Thus, when you use water, the level in the holding tank goes down, and the pump comes back on to replenish the supply.

The other method uses an electric switch to make and break an electric circuit to turn the pump on/off as water is used.

 

[normanwei]

Hi..I have a problem with my aerator valve. Sometime the tank just keeps filling and overflowing the tank. Other times the aerator never came on even when the tank is half full. I took the solenoid valve apart and there was no particles inside and the diaphragms look fine. The knob is now at 2 o'clock position. the pump will run properly if I loosen it somewhat but water is leaking out of the knob. Should this knob be in the one o'clock position? Or does it matter? Where do I find replacement diaphragms? Lowes does not have it. What is the brand name of this solenoid valve?