pressure problem with pump

[lake ainslie14]

You I have a jet pump and bladder tank.
the water pressure is fine when I open a tap. then psi lowers and pump comes on when it reaches 30 psi. but it cannot get back to 50 psi. the pump keeps running as long as the tap is turned on. as soon as you shut the tap the pump gets the psi back to 50 psi and shuts off

 

[John.g]

What is a jet pump and bladder tank?. Is it a negative head pump with a small pressure vessel mounted on top, if so, the pressure drops when you open a tap, the pump starts and will continue to run until the tap is shut and the flow switch detects no flow.

 

[lake ainslie14]

What is a jet pump and bladder tank?. Is it a negative head pump with a small pressure vessel mounted on top, if so, the pressure drops when you open a tap, the pump starts and will continue to run until the tap is shut and the flow switch detects no flow.

you are not familiar with jet pumps? . I have a well with a jet pump and pressure tank in basement. the pressure turns the pump on when get below 30 psi and shuts the pump off when it gets to 50 psi even when the water is running. now it will not reach 50 psi with the water running, that is the problem

 

[Deleted member 123817]

Maybe partial filter blockage? Presume water usage is less than the pump's rated capacity, does it reach 50 psi if usage is throttled in?.

 

[ShaunCorbs]

Is the bladder set correctly ie hasn’t lost its charge ?

 

[lake ainslie14]

Is the bladder set correctly ie hasn’t lost its charge ?

yes I charged the bladder " pressure tank". it was down about 10 psi. but after charging. it is still doing the same thing. I am baffled is it the pump or the bladder tank

 

[John.g]

Is this "pressure tank" ~ 20 litres or so?. or is it part of a bigger storage tank?.
If its a multistage pump then maybe hole in one of the diffusers, you may be able to reduce the cut out pressure by 5 psi or so.

If you can give a reasonable estimate of the pressure vessel size and the pre pressure and time how long it takes to rise from 30 to 50 psi (with no water demand) I can tell you what the pump output is which may help.

 

[lake ainslie14]

Is this "pressure tank" ~ 20 litres or so?. or is it part of a bigger storage tank?.
If its a multistage pump then maybe hole in one of the diffusers, you may be able to reduce the cut out pressure by 5 psi or so.

If you can give a reasonable estimate of the pressure vessel size and the pre pressure and time how long it takes to rise from 30 to 50 psi (with no water demand) I can tell you what the pump output is which may help.

there is only one 20 gallon tank. it only takes a few minutes once the tap is shut to reach 50 psi and shut of. but can never get above 30 once tap is open

 

[Deleted member 123817]

This would indicate that it's pumping - 50/60 LPM in filling the tank. If the pressure stays at 30psi even with the tap just cracked open then that indicates to me that the pump is variable speed and controls the pressure to 30 psi until no demand and then rises to 50psi and cut out.

 

[Deleted member 123817]

Should have said pumping - 20/30 LPM .