High Pressure in pump

[goodoleme]

Hello everyone, I hope someone can help me with this one.

I have a 80 foot well in south Florida. Water table is 6 foot. With a 18 year old Goulds hsj15n with the shallow well package.

I started getting lower water pressure on the system, 30psi, system is setup for 40/60. Drained the pressure tanks and both hade 38psi, all good.

I then looked at the pressure switch and saw it was closed but no pump running, power was good and I disconnected power then repowered, it turned on. I replaced the pressure switch, did not fix it. I did check the start cap and it was within 3% of the MF.

I have a spare new hsj15n, was like ok 18 years is good run, I replaced the pump & with new 40/60 p-switch. With the new pump installed now I was getting down to 15psi cut in and 30psi cut out.

I have a pressure gauge on a t on the discharge line, was reading 20psi also one after my filters, same 20psi. Pressure switch was open. I removed the 1/4 tubing (system was depressurized) from the pressure switch and connected a pressure gauge, turned on and it went up to 75psi, turned off the pump.

With that having 75psi on the 1/4 line the discharge line was reading 20psi, this is why the pressure switch was open. The location for the pressure for the pressure switch is coming from the back bottom right of the pump. This is where the manual says to install and was where the old one was installed.

I did install a new shallow well package with the new pump, did take the old one apart and it is the same venturi and nozzle as the old one. Old one was in good condition, no clogs. Not sure if the jet ejector is causing high pressure inside the pump.

I do have a 25 year old check valve installed at the well that I was going to replace but its not getting stuck open, I don't lose prime and the system does not lose any psi/water in 24/h. No air in the system. Pump runs for 130sec from 15psi to 30psi. No pump short cycling. No p-switch chatter.

Any help would be great, thanks.
Neil

 

[Valveman]

I would replace the gauge. If the switch is open, it is seeing high pressure. If there is high pressure at the switch but not at the pump discharge, the line to the switch is clogged.

 

[Sponsor]

 

[Reach4]

I started getting lower water pressure on the system, 30psi, system is setup for 40/60. Drained the pressure tanks and both hade 38psi, all good.

Air precharge needs to be lower for a jet pump than for a submersible. That is not important yet, because you are not getting even 35 psi.

I have a pressure gauge on a t on the discharge line, was reading 20psi also one after my filters, same 20psi. Pressure switch was open. I removed the 1/4 tubing (system was depressurized) from the pressure switch and connected a pressure gauge, turned on and it went up to 75psi, turned off the pump.

With that having 75psi on the 1/4 line the discharge line was reading 20psi, this is why the pressure switch was open. The location for the pressure for the pressure switch is coming from the back bottom right of the pump. This is where the manual says to install and was where the old one was installed.

I don't I follow all of that. https://www.pumpproducts.com/media/amasty/amfile/attach/Goulds_HSJ_Series_Technical_Brochure.pdf impressive looking pump.

The ideal place for the pressure switch sense line to sense is a close as practical to the input of the pressure tank, but matching the pressure closely works and is convenient. I see that the sense line is connected to the same chamber as the output pipe. Is there a valve between the pump output and the pressure tank?

A photo that includes the pressure gauges, the pump output, the input for the sense line (if not the pump housing as pictured in the brochure), and the input to the pressure tank would help visualize if swapping out the pressure switch does not fix your problem.

 

[Bannerman]

started getting lower water pressure on the system, 30psi, system is setup for 40/60.

Is lower pressure actually observed at faucets, or are you only referring to the pressure gauge reading?

Suggest obtaining an additional gauge equipped with a garden hose connector, so you can periodically, simply measure the pressure directly at a faucet such as a laundry faucet which will often be equipped with a garden hose thread spout.

The location for the pressure for the pressure switch is coming from the back bottom right of the pump.

A pump causes water to be moved by creating a pressure differential. Connecting the pressure switch/pressure gauge sense line directly to the pump, simplifies matters for the pump manufacturer, but may result in the pressure switch shutting off the pump prematurely. When this occurs, the pressure indicated on the gauge will typically drop somewhat, immediately when the pump becomes shutoff while no water is being utilized anywhere.

Suggest using new tubing and fittings to connect the pressure switch/pressure gauge directly to the pressure tank Tee fitting. It's likely there is sediment or other debris stuck within the existing sense line or fittings, which maybe affecting how the gauge and switch is sensing the actual system pressure. The pressure obtained at the tank, will better represent the balanced system pressure as the pressure tank will absorb and balance out the additional pressure spike supplied by the running pump.

Any filters are to be located after the pressure tank & pressure switch.

Drained the pressure tanks and both hade 38psi, all good.

Why is there multiple pressure tanks?

Are they located directly together, or is there some distance between them?

Are both tanks of identical capacity?

I do have a 25 year old check valve installed at the well that I was going to replace but its not getting stuck open,

Is this check valve in addition to a foot valve located at the bottom of the well?

 

[RetiredInGueydan]

Air precharge needs to be lower for a jet pump than for a submersible. That is not important yet, because you are not getting even 35 psi.


I don't I follow all of that. https://www.pumpproducts.com/media/amasty/amfile/attach/Goulds_HSJ_Series_Technical_Brochure.pdf impressive looking pump.

The ideal place for the pressure switch sense line to sense is a close as practical to the input of the pressure tank, but matching the pressure closely works and is convenient. I see that the sense line is connected to the same chamber as the output pipe. Is there a valve between the pump output and the pressure tank?

A photo that includes the pressure gauges, the pump output, the input for the sense line (if not the pump housing as pictured in the brochure), and the input to the pressure tank would help visualize if swapping out the pressure switch does not fix your problem.
View attachment 105576

Air precharge needs to be lower for a jet pump than for a submersible. That is not important yet, because you are not getting even 35 psi.

I have never heard of such. Is this a northern practice due to colder temperatures? Every jet pump down south has the pressure 2psi under cut in, like all pumps.

 

[Reach4]

Air precharge needs to be lower for a jet pump than for a submersible.

I have never heard of such. Is this a northern practice due to colder temperatures? Every jet pump down south has the pressure 2psi under cut in, like all pumps.

The symptom of the precharge being too high is a stutter in pressure when using water at good rate, and the pump cuts on. Unless you have a pressure switch with a lever, you might not notice or care.

With a smaller pressure tank, the pressure differential needed could be bigger. It is one of the pressure tank's jobs to supply water between when the pressure switch turns on and the pump delivers enough water to keep up with the load.

 

[RetiredInGueydan]

The symptom of the precharge being too high is a stutter in pressure when using water at good rate, and the pump cuts on. Unless you have a pressure switch with a lever, you might not notice or care.

Ok, I can see that with a being an issue with a CSV and small tank. Even at full flow, normal sized tanks provide a huge amount of water between cut in an 2psi less.

 

[Reach4]

Ok, I can see that with a being an issue with a CSV and small tank. Even at full flow, normal sized tanks provide a huge amount of water between cut in an 2psi less.

Some would consider a 20 gallon tank to be normal. Others maybe 32 gallons. But certainly a 4 gallon tank used with a CSV would call for a lower precharge than with a bigger pressure tank.

I have no experience with jet pumps. I looked for a graph of jet pump GPM delivery vs time, but I did not find it.

 

[Bannerman]

I can see that with a being an issue with a CSV and small tank

This reasoning would then seem to apply for both jet and submersible pumps.

normal sized tanks provide a huge amount of water between cut in an 2psi less.

A fairly large pressure tank such as an 80 gallon, will hold approx. 20 gallons water between 40-60 psi. A 2 psi pre-charge below 40 psi, will not equal a 'huge' amount.

Using a 38 psi air pre-charge, will signify the pressure tank will contain 0 water once the system pressure is reduced below 38 psi.

Any pump will immediately begin to move water once activated, but 'soft start' pumps, to reduce the initial start current draw, will initially activate at a slower speed, and then will ramp-up to full speed within several seconds

A submersible pump is utilized to only push water in one direction. With the sub pump's built-in check valve, and with no other check valves placed downstream, the drop pipe will remain filled and pressurized by the pressure tank while the pump is not running, so water will be again supplied with no delay once the pressure switch activates the pump.

Because a jet pump may utilize a lengthy suction line before the pump, water will need to be drawn to the pump before the pump can supply pressurized water to the pressure tank & plumbing system. A long length suction line, or one equipped with multiple elbows and other fittings, increases the potential for air leakage into the suction line, particularly if there is a check valve located directly before the pump.

The topside check valve may prevent the foot valve (if equipped,) to not seal fully, thereby causing a vacuum to remain present in the suction line, even while the pump is not operating. Any air that does leak into the line, may cause a delay to occur before water is supplied to the pump, thereby increasing the potential for a water supply stutter (loss of flow) before there is continuous water supplied to the system. A lower air pre-charge such as 36 psi in the pressure tank, will result in a greater quantity of water to always remain in the tank, thereby reducing the potential for water flow to stutter before the pump is capable of delivering continuous flow.

 

[RetiredInGueydan]

This reasoning would then seem to apply for both jet and submersible pumps.



A fairly large pressure tank such as an 80 gallon, will hold approx. 20 gallons water between 40-60 psi. A 2 psi pre-charge below 40 psi, will not equal a 'huge' amount.

Using a 38 psi air pre-charge, will signify the pressure tank will contain 0 water once the system pressure is reduced below 38 psi.

Any pump will immediately begin to move water once activated, but 'soft start' pumps, to reduce the initial start current draw, will initially activate at a slower speed, and then will ramp-up to full speed within several seconds

A submersible pump is utilized to only push water in one direction. With the sub pump's built-in check valve, and with no other check valves placed downstream, the drop pipe will remain filled and pressurized by the pressure tank while the pump is not running, so water will be again supplied with no delay once the pressure switch activates the pump.

Because a jet pump may utilize a lengthy suction line before the pump, water will need to be drawn to the pump before the pump can supply pressurized water to the pressure tank & plumbing system. A long length suction line, or one equipped with multiple elbows and other fittings, increases the potential for air leakage into the suction line, particularly if there is a check valve located directly before the pump.

The topside check valve may prevent the foot valve (if equipped,) to not seal fully, thereby causing a vacuum to remain present in the suction line, even while the pump is not operating. Any air that does leak into the line, may cause a delay to occur before water is supplied to the pump, thereby increasing the potential for a water supply stutter (loss of flow) before there is continuous water supplied to the system. A lower air pre-charge such as 36 psi in the pressure tank, will result in a greater quantity of water to always remain in the tank, thereby reducing the potential for water flow to stutter before the pump is capable of delivering continuous flow.

Huge amount is relative, 1 gallon verses 0 water is huge. If you disconnect the power supply and drain the pressure tank at full discharge, you will be amazed at the amount produced between 40-38psi. This is more than enough water to prevent stutter in a jet pump anywhere on the Gulf coast, where 99% of the jet pumps sit on or adjacent to the casing.

 

[Reach4]

This reasoning would then seem to apply for both jet and submersible pumps.

To an extent, but part of the 2 psi commonly suggested for a submersible is to account for possible diffrences in gauge calibration and altitude. So the extra margin for those differences would not change much.

So with a 4 gallon tank, if 2 psi is enough, you might want 1.1 psi for a 44 gallon tank. That is to say that part would be proportional, and part would not be

 

[Valveman]

An 80 gallon size tank holds about 20 gallons between 40 and 60. That is 1 gallon per PSI. So, with 38 PSI air charge you should get about 2 more gallons out of the tank if the pump fails to come on at 40 as it should.

Air charge for the tank should be the same with jets and subs. If there is air in the suction line because of too many check valves or other reason, then there is a problem than lowering the air charge in the tank will not help. Even though it is a suction line, it should be full of water all the way to the pump and there should be no delay in water after the pump comes on.

There is also no reason for a difference in air charge because of the size of the tank. Small tanks need the same 2 PSI less than pump start as large tanks. When a jet pump OR submersible comes on at 40 PSI, there should be no delay in water regardless of the size of tank.

The only reason to use a lower than normal air charge is for VFD and other soft start pumps that take 5 seconds to get up to speed. Then a lower air charge in the tank can prevent a delay in water as the pump is getting up to speed.

Even with normal pumps I usually say 5 PSI less than pump start instead of 2 PSI. This is mainly because of the difference in the air pressure gauge and the water pressure gauge. 2 PSI is very close and I prefer to err on the low side as having too much air will cause a delay in water production as the tank runs completely empty just before the pump starts.

 

[goodoleme]

Took the pump apart, no disassemble!!, was a gasket! Its's what I get for 2 is 1 and 1 is 0 (AKA NONE). Spare pump sat around in a garage in south fl for 18 years.

Should have done a lead lag pump controller but I pump liquid helium at work, ah the shoe maker story.

Thanks everyone!

 

[Reach4]

Air precharge needs to be lower for a jet pump than for a submersible. That is not important yet, because you are not getting even 35 psi.

I have never heard of such. Is this a northern practice due to colder temperatures? Every jet pump down south has the pressure 2psi under cut in, like all pumps.

Thanks! I was basing my statement on what I had read here earlier. Thanks to your alert, I will re-assess, and others will/have I think.

 

[Reach4]

Thanks! I was basing my statement on what I had read here earlier. Thanks to your alert, I will re-assess, and others will/have I think.

Looking back, I was already saying what now appears to be the wrong thing Jul 6, 2015 https://terrylove.com/forums/index.php?threads/tank-air-pressure.61868/post-458364 I had to have read something along those lines before, because I have had no relevant experience to base that on.

 

[Reach4]

Its's what I get for 2 is 1 and 1 is 0 (AKA NONE).

Being cryptic on purpose?

Should have done a lead lag pump controller

Humor?

 

[Valveman]

Looking back, I was already saying what now appears to be the wrong thing Jul 6, 2015 https://terrylove.com/forums/index.php?threads/tank-air-pressure.61868/post-458364 I had to have read something along those lines before, because I have had no relevant experience to base that on.

I mentioned it a time or two, but you do so good helping people and I thought it was minor so didn't mention again.

 

[RetiredInGueydan]

Took the pump apart, no disassemble!!, was a gasket! Its's what I get for 2 is 1 and 1 is 0 (AKA NONE). Spare pump sat around in a garage in south fl for 18 years.

Should have done a lead lag pump controller but I pump liquid helium at work, ah the shoe maker story.

Thanks everyone!

What is your definition of no disassemble?

 

[SuperGreg]

Being cryptic on purpose?

If you're referring directly to the quoted comment, it's a common statement for people using critically important gear, such as flashlights when cave diving. One will inevitably break so if you only have one, you really have none. Aka two is one, one is none.