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deep well jet pumps
Well dang, two days ago our neighbour's well stopped after spending some time frequently turning on and off while a washing machine was going. Yesterday the neighbours had to go to hospital and now they can't find a well service company that will take the job soon. It's double drop jet pump that lifts water maybe 90'.
Two days ago we fooled around with the pump. The pump was primed through a port on the pump numerous times. The suction line was taken apart and filled with water. The water level in the suction line drops fairly quickly. No attempt was made to fill the drive-line with water.
The pump shows no sign of drawing water when primed in this manner. I know that if an ordinary suction pump line won't hold water, it's almost a sure sign of that the foot valve is bad or the line is broken. I'm not sure if that is true for double drop jet pumps as well. We have a submersible pump one place, and a hand pump at another and shallow well suction pumps other times. I don't know much about jet pumps.
After returning from hospital last evening my 70-year old neighbour and an 80-year old friend concluded that the foot valve is the problem and started probing and digging to find the well head last night. My neighbour wants me to uncover the well head with my backhoe. The well head is supposed to be protected by cedar slabs, and I suppose I could get a much better idea of the exact location and depth. I still wouldn't be too happy about the idea of digging where I don't know exactly what's down there. Wouldn't be good at all doing major damage while trying to help. It also wouldn't be very good to dig a big hole and then find that the pump was the problem. I sure hope somebody shows up who's actually worked on a jet pump before, but any guidance from here is appreciated.
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deep well jet pumps
I am not sure what a double drop pump is. You definately need to prime the pump and repair the foot valve. At 90 feet you would need nearly 90 lb of suction to draw up the water.
The submersibles are less money now in the states. We can get one for that well for less that $300 now. I might be inclined to get a new pump.
Peters
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deep well jet pumps
Tom, I was rooting around in the overgrown brush in front of my house a couple of weeks ago. I stepped on what appeared to be a pile of old leaves that didn’t sound or feel right. I jumped back and found I had nearly broken through a sheet of rotted plywood, which was covering a 3-foot deep hole over my septic tank. Turns out the former owner (also an old duffer) thought it best to leave the top of the septic exposed and stacked three large car tires in the hole and threw a piece of scrap plywood over the top. I shudder to think what might have occurred if I had driven the tractor over this booby trap before I found it. Be careful looking for that buried wellhead!
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deep well jet pumps
Tom;
Is the well casing metal? If so it might be best to see if you can find it with the metal detector before you dig. I would spray the position on the grass with a can of paint and then dig gingerly.
Peters
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deep well jet pumps
Tom, around here the well guys carry a piece of re-bar about 8' long. This is used to probe for the well-head and when it is found it is left in place as a marker so that the backhoe operator knows where it is too. Once the well is located I strongly recommend setting a conventional well tile over it, resting on a base of gravel. This will make any future access much easier. Tip of the week time, if you hang a compass vertically by a piece of string it will go crazy when you get near the well, this is because of the magnetic flux emanating from the steel casing stuck down into the earth acting like a 'magnetic antenae'. Best of luck.
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deep well jet pumps
Good tips. Thanks.
After I posted here I did a quick search and quickly found a description of jet pump workings. Basically, a double drop jet pump is for deep wells. There is a suction line and a drive line to the well. The drive line carries water from the pump under pressure to a Ventura unit in the well. The Ventura develops pressure that gives water a push up the suction line. Apparently jet pumps can work to 200' but not very efficiently. If there was any doubt about the prime, filling the suction line with water should have done the trick and a bad foot valve likely is the reason water won't stay in the line.
As it turns out my neighbour's friend (ours too) has worked on jet pumps many times so at least there was some real experience available and I was happier. He even mentioned the compass trick. I have a 6' piece of rebar but the ground in the area was way too hard to probe. We lucked out and found the head without too much difficulty. It is 5' down, and I don't know if the compass trick or a cheap metal detector would have worked.
We lucked out and found the edge of protection for the line, and that gave us an angle to follow. We trenched along the angle beside the line protection (I'm still not sure exactly what it is but it's covered with vapour barrier. We undercut the trench side with hand shovels and followed the plastic and hit a cement block with some rotted cedar nearby. The block turned out to be the corner of a 3' x 3' x 3' cube of cedar covered cement blocks that contained the well head. The blocks are a substitute for a well tile.
We’ll likely finish today and the neighbours might even have water when they return from their second 6-hour round trip drive to hospital. I did learn a tip in doing this work. When we realized that we'd have to 'fish' for the lines and head, my inclination was to trench across where the lines had to run. The friend's inclination was to trench three buckets wide in the direction the lines run. 'Less chance of hooking a line if they're not protected' he said. The value of listening closely to people who have been around these sorts of projects for decades was reaffirmed--even if they don't know how to operate a hoe. That's a tip to remember I think.
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deep well jet pumps
I wonder if anybody has an idea of how large a volume of air a casing breather has to vent into?
The cube of cement blocks wasn't filled, and a pipe nipple for the vent comes out of the casing cover. It was just covered with a glass fruit jar (amazing that we probed all around looking for the well head and never moved or broke the glass jar.
Our inclination is to fill the cavity with sand, cover the top with plywood and top with foam insulation and then cover the whole thing with vapour barrier. Now I'm wondering if the idea might cause inadequate venting. Sure would be unpleasant to go through all work fixing the foot-valve and then have a pump that stops working every time there's heavy use.
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deep well jet pumps
If the pump is pumping the water into the tank to fast the pump will loose its prime...
A valve between the tank and the pump will slow the water down untill the pump can get started...
I close the valve all the way and turn on the pump... When the pump stalls I open the valve slowley... After 40 lbs of tank pressure I open it up all the way...
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deep well jet pumps
Kevin: Thanks for the comment. I think that gives me an explanation for the priming procedure in the pump manual. I suppose the pressure valve could be bad but the pump is only 6-years old even if the well is 30 years.
We took off the suction line, filled it with water, and it wouldn't hold the water. That seemed to point toward a bad foot valve. Yesterday we pulled up the well line, and the foot valve was definitely stuck open. The injector unit (about 60' down the well) is caked with rust and deposit. The manual says a clogged injector can prevent the pump from working, and the injector should be cleaned. Of course, the manual doesn't say how. There always can be more than one problem, but I hope the foot valve is the explanation. Of course, we need a new cover since I managed to drop part of a cover bracket down the casing--part stupid on my part and part stupid in the original installation. It might not have been such a bad thing since the rubber gasket probably should be replaced on principal.
After 30-years, I'd be inclined to put new everything down the well but I doubt my neighbour will spring for the costs. Don't know how happy I'd be digging up the well head again in a couple years and maybe in the middle of winter.
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deep well jet pumps
Rebuilt the contacts on a submersible pump the other day. Could not find any parts as the submersible was more than 25 years old.
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