Low GPM but good pressure

[Mispeld]

Sorry for the long description as I am trying to be thorough. I posted once or twice before and I gave bad information regarding the depth and would like to clarify to see if I can figure out why my GPM is so low.

We have been using our well on the weekends to provide water to our camper. We have been using about 250 gallons per month for the last 5 or 6 months. It has been reliable and been working great for us since installing a large pressure tank. But my gut tells me 1.2 GPM at 18.3 amps isn’t right considering the data plate says 4GPM.

Background:

I purchased a small 30-acre farm in eastern NC in 2021 that had been dormant for 7 years. We are pretty much at sea level with no hills or rocks and the soil is sandy loam. The property has 3 wells total and two are old 15-20ft (guessing on depth) shallow wells that go dry during droughts. I assume with good reason this deep well was installed for reliable water for the 10-15 cattle that once occupied the land. The well was installed in 2010 and has not been used in the least 7 of the years since but still had a full tank and pressure after sitting for many years.

The pump draws 18.3 amps & about 75psi while running but has low volume - produces 1.2 GPM based on my calculations and with the flow meter. The pressure seems fine to me. It takes a while to fill the pressure tank (obviously) and shuts off at 60psi as it should and holds pressure. The old pressure tank was full after 7 years and nothing bled down.

Last year I pulled and removed the 80’ inner pipe from the 2” casing and it seemed ok but I really don’t know what I am looking at. There wasn’t anything screwed into the bottom below the leathers so I am curious if anything was ever there and fell off or if it is supposed to be this way.

Can anyone give me any ideas or input? All I can think is maybe there is a restriction or something? Would a broken casing cause this? Is the 18.3 amps normal?

Below is directly off the well casing data plate and motor data plate:

Data plate on the 2” Casing…
Date Completed: 7-12-2020
Casing Depth: 230 ft
Screen Interval: 230
Gravel Interval: 225
Static Water level: 10
GPM: 4
Pump Brand: Berkely
Model#: 10MS
Depth of pump: 80
Volts: 110

Data plate on Pump Motor…
Berkeley
Motor# 48L2FC4VHC3
Pump Model No: 10MS
HP: 1
3450 RPM
MaxLoad Amps 19.2
S.F. 1.65

 

[Fitter30]

Here's a manual for ur pump. Can have two different nozzle sizes at 80'. 4.9 & 6.5 gpm @ 60lbs. Look at page 6

https://www.google.com/url?q=https://www.pentair.com/content/dam/extranet/web/nam/berkeley/manuals/be757-1-ms-series-multistage-deep-well-jet-pumps-iom.pdf&sa=U&ved=2ahUKEwj8s4XhgO6AAxW1lYkEHRGvAR8QFnoECAYQAg&usg=AOvVaw0zyt27-UINAYYZjp1jDZeA

 

[Sponsor]

 

[Reach4]

There should have been a foot valve below the ejector.

A foot valve is a combination check valve and intake screen screen.

There can be a pipe between the ejector and the foot valve. If that pipe is over about 35 ft long, the well can never suck air. But if that pipe is shorter, such as 10 ft, that would let the system still draw water if the water level fell to almost the level of the foot valve.

 

[Valveman]

Yeah there should be a foot valve screwed onto the bottom of the ejector. Don't know how it is holding pressure after the pump shuts off without a foot or check valve? The leathers on the ejector might not be sealing as they should, which would cause a loss of flow. Also, have you tried just adjusting the back pressure valve? Adjusting the back pressure valve for the max flow maybe all you need to do.

 

[Mispeld]

Thanks for the input. Is the "back pressure valve" where the gauge is? I tried. I adjusted it for max flow and to steady the needle and it's running about 75psi when it's on. It helped but didn't yield the results I was hoping for.

 

[Valveman]

I would think 75 on the back pressure gauge is enough. Maybe the jet nozzle in the ejector is clogged or worn. I would try the larger GPM nozzle as Fitter suggested.

 

[Mispeld]

Update: I removed the 80’ of piping and ejector. The casing of the ejector is stamped according to the chart above and adequate for the 80’ depth. I did not remove the nozzle though. Just for the heck of it, I decided to lower the drop pipe 50’ instead of 80’ to see if there would be a difference… but I did not notice one in the short time I had the pump on. Within a min or two, I learned that my glued joint did not hold and I lost 30’ of 1” PVC piping with the ejector and it was sitting 230’ at the bottom of my 2” casing. Ugh!!!

I ordered a 2” submersible pump from Amazon thinking worse case – leave the 30’ section of drop pipe in the bottom and try to modify the pump and see if I can make it work down the small 2” casing.

In the meantime, I figured why not try to get the old one out? What’s difference if it’s 10’ or 200’? I made a tool out of 3’ piece of ¾” metal conduit, other parts, and two 250’ 1/8” braided cables to engage and disengage the contraption. It took a good part of the day since we went slow due to the amount of force to pull it, but we got it out.

Now I have the ½ HP 2” submersible pump with ½” fitting for the drop pipe. I had to grind down some pultruding screw heads to get the pump to fit into the PVC. It is tight, but it slides in. I used 5/8 irrigation tubing just to see if this will work before I invest in new wire and ½” drop pipe (or maybe try ¾”??).

I dropped it 80’ and it produced right at 4.0 GPM and then tapers down as it continues to run. It will run for about 5 ½ - 6 min producing about 18 gallons before the pump uses all of the water above it. The water in the well casing recovers within minutes.

I hooked it to the 36 gallon pressure tank that was set up to 40/60. The new well pump started ok but the GPM continuously dropped while filling the tank. I can only get to about 44psi producing about .05 GPM under that pressure. I had to adjust the pressure switch and tank PSI.

Moving forward – I am waiting on the wire to arrive and I am going to replace the drop pipe probably this weekend. I might drop it further down to about 100’ or further to see what happens. I predict longer runtime but fear the PSI and volume may suffer. I am also going to slightly modify the pump housing with little room I have left to increase intake flow – if possible. But it looks like the 2” submersible pump just might work for my application inside my 2” casing. Again, we use about 250 gallons with our camper so maybe I can get this dialed in.

Is the reduced GPM normal and inability to build pressure beyond 44psi? Should I try to drop it deeper or will I further be depleting the PSI and volume capabilities?

Specification:
Model: 2QGD-220V/60Hz
Color: silver
Voltage: 220V-240V/60Hz
Power: 0.37KW, 0.5HP
Max. head: 55m/180ft
Max. flow rate: 1m³/h, 4GPM
Speed: 3420r/min
Outlet: 1/2 inch

 

[Valveman]

That pump can only make 77 PSI max. That means it can't reach 60 PSI for a 40/60 switch if the water level is deeper than about 30'. Reviews also say it only last 10-12 months. I think you would be better off getting the jet pump to work as they can last 40 years.

It doesn't matter how deep you set the pump as it only lift from the water level, not the depth of pump setting. You could probably use that pump to fill a cistern, as that doesn't require any pressure, and would let that pump work until the water level drops to more than 150' deep.

 

[Mispeld]

Thanks. So I guess I am in the ballpark with my theory that I can't achieve 60psi with this pump at the depth and other limiting factors. I was considering a storage tank in the future if the planets and stars align when we build our house. We got an estimate of $10k for a new well so I am hoping this one can get us by until we are ready for an upgrade. The 2” casing is really limiting.

I appreciate the input. I have never messed with wells and pumps so I am learning.

 

[Mispeld]

I re-read what you wrote valveman "It doesn't matter how deep you set the pump as it only lift from the water level, not the depth of pump setting."

So what you're saying - and please correct me if I am wrong...

If the water level is 15' down the casing, and I drop the pump 150' - then essentially the pump will actually be working from a simulated depth of 15'?

I was puzzled when I saw 4.0 gpm when I first turned the pump on and it decreases as the water level is reduced in the casing. Now I know why if I am interpreting what you're saying correctly.

I wish I could just figure out the jet pump and get that working. I should get off my wallet and hire someone.

 

[Valveman]

Yes. You can set the pump at 1000' and it is only lifting from 15' if that is the water level from the land surface.

Fixing the jet pump shouldn't be that hard. But it is hard to bucket test one of those. You just have to put it in the well and see if it works. Setting the packer at a different spot in the casing so the leathers will seal maybe the only problem.

 

[Mispeld]

Awesome. That is interesting. I guess pump depth won't matter much if my water level is 15' from the surface.

I wish I could figure out what is wrong with the jet pump. Leathers are good and seals fine – never had a problem holding pressure or losing prime. Back pressure valve has been adjusted. Well isn’t too old (2010) and has not been used for 7 of those years. It has had very light usage on the hobby farm. Plate says 4 GPM. I just can’t seem to figure out why it can’t produce anything more than 1.8gpm running at 18.3 amps. PSI is great. Maybe it’s the pump. The submersible seemed simpler and cheaper. It also only consumes 2.5 amps (240v).