Sciencey odd question just occured in my daily musings...

[ecowarm]

Pressure Drop: Calculation of pressure drops in pipes look here save all the messing about

 

[fuzzy]

spoil sport

 

[stevetheplumber]

we once joined 5 long hose pipes together to refill a pond and it barely trickled out despite being on a main

 

[fuzzy]

over 50,000 meters it drops 58,000 bar!!!! yikes

 

[fuzzy]

we once joined 5 long hose pipes together to refill a pond and it barely trickled out despite being on a main

lies, pure utter lies

 

[fuzzy]

it was a swimming pool

 

[unguided1]

Ah so the water is not fully contained fully and subject to evaporation, expansion, contraction plus its not pure water as it has chemicles in it

 

[fuzzy]

i clicked 'like' unguided, im not sure why because i dont understand what you posted, im sure if i did understand i would have liked it

 

[unguided1]

If I knew what I was talking about half the time I would sound more intelligunt than I look!!!!!!!!!!!!

 

[unguided1]

Sorry but I have to say that chemicles in swimming pools are really interesting I recall back in 1990 I was learning to scuba dive with a local BSAC club and they used to use a girls school swimming pool, anyway after a rather energetic pool session doing diver rescues I commented to one of the caretakers that I had never been in a salt water pool before. whent back a week later and the pool had been drained and fresh chlorine put in !!!!!!!!!!!

 

[quality]

I could not be bothered to read all the other posts , But to the OP - pressure volume flow mass are all proportional
Pressure is force / area ie, pounds of weight over inch of area or metric equivalent.

1 pound of weight on 1 square inch is 1 psi

All you need is the mass (weight) and the pressure (force) and the density (volume) then its simples

 

[fuzzy]

your so last year quality, weve surpassed that, some bloke called reynolds got involved, it all went pear shaped then

are you up for our ukplumbingforum experiment?

 

[quality]

your so last year quality, weve surpassed that, some bloke called reynolds got involved, it all went pear shaped then

are you up for our ukplumbingforum experiment?

Its been a long day but yeh I am up for anything

 

[fuzzy]

do you have 25 mile of copper on the van?

diamondgas wants to do it in speedfit, but i think thats cheating, in fact ive decided hes a big wuss now and i o longer consider him a real plumber, psss, dont tell him

how about doing it in iron? ive got some hand dies

 

[quality]

Their big them dies then

 

[ecowarm]

can we do t in 2" with the hand dies please

 

[quality]

100mm @ 4 bar straight run 25 miles = well enough for combi ( about 112 lpm) guestimated

 

[fuzzy]

dont worry they are electric, has anyone got a 25 mile extension lead?

in fact is the power the same, more or less on a long extension lead? what are the friction losses?

 

[quality]

I get the jist
The power output (work done ) will be what it is determined by the power input (work Supplied)

 

[WaterTight]

I'm not still convinced by (mainly because I don't understand half of them) the arguments given so far. So I'll modify the question..

Ingoring pumps or the nature of the force that has created the pressure, ignoring friction or other factors. Imagine there is a hyperthetical pipe potentially as long as the universe itself if need be. At one end is say 1.5 bar pressure. At the other end a tap. This pipe has no friction, it has not fluctuations of temperature. It's dead-level.

The question to which I want a yes or no answer is.....Could this pipe be long enough so the weight of the water itself to be moved by the standing pressure be so great that the pressure couldn't shift it? Yes or no people, time to vote...

*countdown music*

 

[unguided1]

NO there is no gravity in space therefore the water would be weightless

 

[tamz]

And if there were no friction it would be frictionless

 

[ecowarm]

so if you opened the hypothetical tap you would just release the pressure and that would be it

 

[WaterTight]

And exactly the same experiment but on Earth....?

 

[tamz]

If there is no friction then there are no friction losses so the pressure remains constant

 

[ecowarm]

If there is no friction then there are no friction losses so the pressure remains constant

But he said no pump so how do you maintain said pressure in a level pipe how ever long?

 

[tamz]

Never noticed that bit:shame:

So, if i've got this right, we have a level pipe of infinite length with no applied pressure but as it is on earth, it is subjected to gravity.
Cut the end off the pipe and it will empty...............eventually.

 

[ecowarm]

Glad we didn't get into the electric losses that some one posted as well

 

[mickie]

if your talking about a pipe in outer space their wouldnt be any pressure and if you opened each end water wouldnt flow anywhere, it would stay still, untill someone moved it, using a force of pressure or gravity moved the water down..

 

[tamz]

Ah, but we are now back on earth (post 59) so subject to the usual forces :lol:

 

[mickie]

water run level for a long distance, say 1000 miles, i dont think would work, due to the moons pull on water, just look at the sea, it goes in and out, but i think it would work if the water was raised up from the ground, as that would increase its pressure..its pressure would never come down over the 1000miles, but its flow rate would due to friction so you'd have to fit the currect sized pipe to cater for its run

if size didnt matter, the water board would be using 15mm pipe under our roads to feed everyones home.. i dont know the math in sizing water mains though

 

[tamz]

So the pipe might have a high and low tide:speechless:

 

[mickie]

well if run totally level without any real pressure, bar its own pressure due to its own weight on the earths gravitational pull and say we had no moon, if you opened each end water would flow out slowly, but factoring it the moons pull on water, depending on where the moon was water would naturally want to follow the moons path, would it not ?

dont really understand the question, who'd want to fit a pipe without increasing its pressure

 

[tamz]

I suppose as long as the money was right , wgaf. Just keep laying pipe. No pressure as it is an infinate job!

I'm out:sleep1:

 

[fuzzy]

if your talking about a pipe in outer space their wouldnt be any pressure and if you opened each end water wouldnt flow anywhere, it would stay still, untill someone moved it, using a force of pressure or gravity moved the water down..

there is gravity on the moon, its just reduced 1.6n/s/s instead of 9.8n/s/s. So i pipe on the moon 25 miles long would take 1/6 of the time to empty. However, if it were pumped and pumped upwaards the restriction due to gravity would be less, its all pros and cons lads