Pump

What is the color of the pump, please?

"The pump color is as relevant as any of the other information..."

Exactly. Extraction of applicable information often seems a larger chore than the solution to the problem itself.

All the way to the end of the pipe.

The orientation of the pump is not important. The elevation rise of the fluid being pumped might be of interest to someone doing flow calculations.

The type of pump might make a difference too.

I suggest you go on-line and find an elementary pump website that will explain this in simple terms.

We don't do homework here.

PumpCalcs - Online pump calculations

Suppose the pump rating has discharge pressure of 7kg and the pipe connected to the pump is made open in horizontal direction. To what distance the water will travel..

The water will travel to the end of the pipe. That will be the distance.

I said before, we do not do homework.

You provide no useful information, I gave you a site. You should use it.

Unanswerable; it depends on how high the discharge point is above the ground.

Suppose the pump rating has discharge pressure of 7kg

The rated pressure will not be the operating pressure with an open pipe.

Calculate the speed of the fluid flow. Once the fluid is flowing in the atmosphere, it will have near atmospheric pressure.

A little less than a kilometer, somewhere around 950 meters.

Assuming:

1. the pipe is perfectly straight

2. the pump discharge pressure into the pipe is measured at the lowest part of the pipe cross section

3. the pipe is horizontal to the ground at the point of the pump discharge, and at that point the lowest part of the pipe is at sea level

4. the pump moves water slowly such that momentum plays almost no roll when the water first moves down the pipe.

5. the Earth is reasonably uniformly spherical in the nearby region

6. that the center of gravity is close to the center of the earth and approximately 6378 meters below the lowest part of the pipe near the pump discharge.

7. the pressure listed is gauge and not absolute.

8. Evaporation, vaporization can be ignored.

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Given the above, a straight pipe horizontal to the ground at a starting point will be sufficiently high to prevent a pump providing 7 kg/cm² (gauge) discharge at sea level from pumping water any further.

That's a trick answer.

Statement # 1 and statement # 5 are in direct conflict.

Lyn,

What are you saying?

The pipe being straight does not conflict with the earth being spherical....

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at least not that I can see at the moment. Am I missing something?

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Yes, the value of the earth radius. If it would be as you wrote there is a conflict.

Please be specific about the nature of the conflict.

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What I am describing is a long straight pipe (hollow right cylinder) that sits on the surface of a oblate spheroid, such that it is perpendicular to the normal (of the surface of the spheroid) at the point of contact.

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What I am describing, if viewed in silhouette, could be a circle and a line tangent to the circle. The circle would represent the earth and the line would represent the bottom of the pipe.

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Since the line is straight and the circle is round, assuming the circle has the same radius as the earth, then roughly around 1 kilometer (okay, just re-ran the numbers to double check and definitely had an error, so perhaps this is what what being noted?) 30 kilometer away the bottom of the pipe will be roughly 70 meters above ground which should be about the limit of a pump that is providing 7kg/cm² gauge discharge at ground level.

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OK so was it my large calculation error... it should be 30 kilometers and not 1 kilometer,....that drew the comments stating there is a conflict?

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If not, please help me understand what I am missing.

Two corrections:

'950 meters' should be '29,900 meters'

and

in #6 the radius of the earth was off by 3 orders of magnitude since it should be 'kilometers' not 'meters'

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Thanks to Lyn and Nickname for their persistence in pointing out my error.

Dear Mr. kspathi,

It is the frictional head loss that counts. If horizontal length is wiping out the pressure of 7 Kg/cm^2, then there won't be any flow. You have to use the formula H = 4f x L x V^2/ 2 x g X d and hence L is know for the pressure specified by you.

here, you convert 7 Kg pressure to Metres, f = friction factor, v = Velocity of fluid, g = gravity, d = dia of Pipe. Your question, it appears to me as hypotheticalone.

DHAYANANDHAN.S

You need to ask Lyn for his definition of "pipe".

1. All pipe is to be made of a long hole, surrounded by metal or plastic centered around the hole.

2. All pipe is to be hollow throughout the entire length.

3. All pipe is to be of the very best quality, preferably tubular or pipular.

4. All acid-proof pipe is to made of acid-proof metal.

5. The O.D. (outside diameter) of the pipe MUST EXCEED the I.D. (inside diameter) otherwise the hole will be on the outside of the pipe.

6. All pipe is to be supplied with nothing inside the hole so water, steam, or other stuff can be put inside the pipe at a later date.

7. All pipe is to be supplied without rust, as this can be more readily put on at the job site.

8. All pipe is to be free of any covering such as mud, tar, barnacles or any form of manure before putting up, otherwise it will make lumps under the paint.

9. All pipe over 500 feet in length must have the words "Long Pipe" clearly painted on each end so the fitter will know it is a long pipe.

10. Pipe over two miles long must also have "Long Pipe" painted in the middle so the fitter will not have to walk the entire length of the pipe to determine if it is a long pipe or not.

11. All pipes over six inches in diameter is to have the words "Large Pipe" painted on so the fitter will not use it for a small pipe.

12. All pipe closures are to be open on one end.

13. All pipe fittings are to be made of the same stuff as the pipe.

14. Pipe specified as "Straight Pipe" shall not have fittings within its length, otherwise it becomes "Crooked Pipe."