Weight of water

[MossRoad]

Yeah, it would - if the big pipe was filled it would reduce the small pipe down force. But it wouldnt be a pump if the small pipe couldnt be moved up/down. That inner check valve is the piston.

OK, I went back and read the pump description. Now I'm wondering why the OP is concerned about the weight of the water in the jacket and not the weight of the water in the smaller pipe? Doesn't the water come up the smaller pipe?

 

[Egon]

Then smaller pipe is acting as a pump rod. It’s blocked off and not filled with water. The size of the casing is irrelevant. The water lifted is a column the diameter of the topmost check valve.

 

[MossRoad]

Gotcha. Thanks.

 

[dodge man]

My college degree is in civil engineering but I spent my career as a land surveyor. My daughter is a recent civil engineering grad and is trying to pass the national test as an engineer in training. This problem is the kind of stuff they put on the test. She had a sample test and I thought I could probably get half of them right. I’d be lucky to get 25% of them right. They had 3 or 4 surveying problems on it also and I got one of them wrong. When I first read the Op’s question I knew I could figure it but though this is gonna hurt so I passed.

 

[fried1765]

My college degree is in civil engineering but I spent my career as a land surveyor. My daughter is a recent civil engineering grad and is trying to pass the national test as an engineer in training. This problem is the kind of stuff they put on the test. She had a sample test and I thought I could probably get half of them right. I’d be lucky to get 25% of them right. They had 3 or 4 surveying problems on it also and I got one of them wrong. When I first read the Op’s question I knew I could figure it but though this is gonna hurt so I passed.

Civil Engineer here also, 80 years old.
Considered it too.....but....went back to my nap!

 

[rScotty]

No, I have a second cased hole in the ground that was given up on and Id like to see if I can get any type of recovery rate from it, I dont want to invest alot of money with buying a pump until I know that it has a recovery rate period so I am going to build a hand operated deep well pump.

There seems to be plenty of physics savy TBNers willing to help, but also some confusion about whether what is needed: Is it the weight of the water column in pounds, or is it the pressure of that water column in pounds per square inch?

Maybe if you could make a sketch of the intended hand-operated well pump we could all get on the same page. And maybe learn something.

Pumps curves can be lead to odd pump decisions. Right now I'm using a 110volt deep well pump in a shallow 4" diameter irrigation well because what I wanted was higher flow rate. That seems backwards, but the pump curve shows that deep well pump which is designed for high pressure deep wells actually puts out a lot more volume per amp than my special low pressure/high volume pump.... but only when working real shallow.

Did we discuss using your second cased well a few years ago for a settling/watering pond? Is this the same one?
rScotty

 

[1930]

There seems to be plenty of physics savy TBNers willing to help, but also some confusion about whether what is needed: Is it the weight of the water column in pounds, or is it the pressure of that water column in pounds per square inch?

Maybe if you could make a sketch of the intended hand-operated well pump we could all get on the same page. And maybe learn something.

Pumps curves can be lead to odd pump decisions. Right now I'm using a 110volt deep well pump in a shallow 4" diameter irrigation well because what I wanted was higher flow rate. That seems backwards, but the pump curve shows that deep well pump which is designed for high pressure deep wells actually puts out a lot more volume per amp than my special low pressure/high volume pump.... but only when working real shallow.

Did we discuss using your second cased well a few years ago for a settling/watering pond? Is this the same one?
rScotty

No never discussed it as the wells were not drilled until recently.

I will try and keep this thread going as I go along, if anyone were to check out the link I gave to building a hand pump and reading the information Im sure it will clear any confusion.

At this point my one way check valve is a bust because the valve that I purchased that was advertised as being one size was listed incorrectly so Ive decided to build my own. I believe I will have success with my version.

 

[Egon]

If the proposed pump is being rebuilt consider a redesign which will have a better seal between the plunger and casing. Also look at top valve that uses a ball and seat rather than a check valve. Both check valves could be replaced by ball and seat.

 

[kenlip]

Area = radius ^2 x pi

Outer pipe area = 1.03^2 x pi = 3.339387648 sq inches
inner pipe area = 0.657^2 x pi = 1.358128992 sq inches
Area of gap = Outer area - inner area = 1.981258656 sq inches
Length of pipe = 1200 inches
Volume of gap = Area x length = 2377.510387 cubic inches
Density of water = 0.036126842 lbs/cubic inch
Weight of water in gap = Volume x density = 85.89194211 lbs

 

[Grumpycat]

There seems to be plenty of physics savy TBNers willing to help, but also some confusion about whether what is needed: Is it the weight of the water column in pounds, or is it the pressure of that water column in pounds per square inch?

Ditto. Matters not the weight of the water only the height (head) to be lifted which determines minimum PSI to push more water into the bottom of the column. After one determines this minimum one can start considering the pump performance curves for the rate one wishes the water to flow.

So he is using a windmill-like reciprocating rod down the center to drive a pump at the bottom? Diameter of the pipes still does not matter. Diameter of the piston in his pump matters. Force (pounds-force) on the rod times area (square inches) of the piston for PSI.