High pressure at well (90-100) 40-60 at house

[Lamar]

Friction does not come into play when the pump is not running which it shouldn't when reaching the cut-in. Only after the pump has started would the pipe friction show as an increase in pressure. So cut-in pressure at the wellhead should be 45 PSI, not 92 PSI.

Yea, I'm seeing that now, thanks for helping me better understand. Looking more and more like there may be a partial blockage. But wouldn't it have to be pretty significant to create some 40+ pounds loss in pressure. How would I ever determine where the blockage might be. Do they make a waterline camera?

 

[Bannerman]

I have a new 36 gal diaphragm pressure tank at the well for extra storage for use with livestock watering and small amount of landscape watering.

FYI, extra storage for those uses is not what a pressure tank does, but that is another topic to be discussed another time if desired.

It appears you have been using a 36-gallon pressure tank at the wellhead for at least the past 10 years. Is the excessive pressure at the wellhead a recent development, or was it existing prior to the 10-year-old tank bladder going bad?

If this is recent, perhaps a piece of ripped bladder may have broken free from the old tank and is now stuck somewhere in the line between the new tank and the pressure switch.

 

[Sponsor]

 

[Lamar]

Is the excessive pressure at the wellhead a recent development, or was it existing prior to the 10-year-old tank bladder going bad?

It only became known to me when the new deep well pump was installed approx 3 years ago. The 36 gallon tank I just replaced was installed in 2011, it replacing another tank with another bad bladder.

 

[Greenmonster123]

The only backflow preventer is at the wellhead and no other valves that I am aware of.

I would check your backflow preventer. Checks can get hung up and cause restrictions

 

[Valveman]

A 36 gallon size tank only holds 8 gallons of water just like the 80 gallon tank only holds 20 gallons of water. Your water comes from the well and is supplied by the pump. The only purpose of a pressure tank is to limit the number of on/off cycles for the pump. It does sound like a restriction, could even be a crushed pipe in the line. The restriction is causing high pressure at the well head. As long as it isn't fully restricted the higher pressure won't hurt anything. It just makes the pump think the well is deeper. 1 GPM is all you need flowing to keep the pump cool. So, as long as the restriction still allows at least 1 GPM through, it won't hurt the pump.

With float valves and water for livestock a Cycle Stop Valve will eliminate the cycling when using more than 1 GPM, and large pressure tanks can't do as good a job and are not even needed.

 

[Lamar]

The only purpose of a pressure tank is to limit the number of on/off cycles for the pump.

Guess I used the term "storage" too loosely then, but yea, "limit the number of on/off cycles" that's pretty much what the well guy said 25 years ago when he switched the 1 hp to a 1.5 hp and seeing how much water was being used for landscape watering and livestock. Wonder why he didn't recommend a CSV, lol.

Since the livestock and landscape watering is only at a fraction of what it was 20 years ago and since learning the tank was never of great benefit anyway, at this point, looks like I no longer need the new A.O. Smith 36 gal pressure tank. I'll just leave it unhooked and keep an eye out on the pipeline between the well and house. Maybe install an adjustable pressure relief valve and gauge for monitoring purposes.

Anybody need a great deal on a new A.O. Smith 36 Gal pressure tank, only used once.

Thanks @Terry for this great forum and thanks everybody for all your help, my only regret is not coming here sooner.

 

[Bannerman]

Assuming there is an actual obstruction and that it is moveable (vs a crushed pipe), it may be worthwhile reversing flow to possibly dislodge and eliminate the obstruction.

You mention having installed a ball valve but it sounds as though that valve is only in the line to the 36 gal tank. Are there any other valves between the wellhead and the 86 gallon tank?

If there is an isolation valve somewhere before the 86 gallon tank, with that tank filled to capacity, close the valve. With the pump shut down, disconnect the poly pipe at the wellhead downstream of any check valves so the line to the home will be open and unrestricted. Upon opening the isolation valve fully, the 23 gallons, 60 psi water contained within the 86 gallon tank should then flow back to the pump house and out from the open pipe and hopefully, flush-out whatever obstriction that was lodged within the pipe.

 

[Reach4]

If you ever change the pump, a 3/4 hp pump will probably be more appropriate. A house seldom uses more than 1o gpm.

Pipe pressure drops are a sum of drops through fittings and straight paths. You might try a pressure drop calculator, and compare the pressure drop you see with what would be expected. http://www.pressure-drop.com/Online-Calculator/ One-inch pvc is a tad over 1 inch ID, so you could just enter 1 inch diameter as close-enough.

If you time how long it takes to fill a 5 gallon bucket from a hose spigot on the house, or bath tub faucet, you would know the flow rate for your test.