Just as a matter of interest ... is it possible to work out how much water is contained in a pipe that is 8 kilometres long and one and a half inches in diamater?
Thanks

(Tabby Tom, if anyone can do this, it will be you!! )

That would be 8800 liters.

Wow, that was quick! Thanks Leau!

Is the diameter an inside one or to the outside, how thick is the pipe?

Use the formula lenght * ¶*R².

assuming an inside diameter of 38.1mm this yeilds 8000000*3.1416*19.05*19.05
= 9120734624 mm³ or 9121 litres

Do you know, Alan, I'm just going to sit here and look intelligent and nod my head knowingly at your reply. (thanks!)

It's not very thick, perhaps 5mm all together? (it's just black poly pipe, if you know what I mean) and I don't know if it's the inside or outside, I would assume inside. you both got different answers ... but either way it is a lot of water

My calculations were exactly the same as Alan's, except for the fact that I used 3.14159265358 as pi instead of 3.1416, so that leads to some liters difference.

Copago, with the present weather conditions, I would be surprised if there was *any* water in the pipe...

was the pipe 'closed' in the first place? It could have been a HOLLOW cylinder!

lol, you're right, Ozzz! We ran out of water at our house about two months ago and have been carting water since so had to put in the pipeline from a bore ('unlimited' supply) so now I can turn the tap on without feeling guilty It's expensive but already it's worth it ... last night I had a shower for about 15 minutes. Ahhh bliss.

You run a pipeline of eight kilometers? How is the water pressure?

Seriously, that makes me feel humble and guilty, water is just something we take for granted.

I just know I am going to regret asking this Copago but why do you want to know how much water you have in your pipe?

Most piping is sized and sold by "nominal bore" which refers to the internal diameter. The nominal means that the internal diameter may vary quite considerably from the quoted bore (in this case 1.5").
The thickness of the pipe normally depends on the expected difference in pressure between the fluid inside the pipe and what is outside it. The larger the difference in pressure the thicker the pipe wall needed.

I looked up a typical plastic water supply pipe and for 1.5" nominal bore the internal diameter is 1.253" (31.826 mm), the external diameter 1.625" (41.275 mm), this gives a pipe wall thickness of 4.724 mm.
I also looked up the size of a typical plastic pipe for light geothermal use as I thought if you are using a bore hole you might have a high pressure supply. In this case the internal diameter is 1.478" (37.541 mm), the external diameter is 1.9" (48.26 mm) and the pipe wall is 5.360 mm.

So if your pipe were exactly 8 km long and perfectly straight (which of course it isn't) the volume of water would be equivalent to a that of a cylinder 8 km long and the internal diameter wide. The formula for the volume of a cylinder is; Pi times the diameter of the cylinder squared times the length of the cylinder divided by four. Pi is a ratio of the circumference to the diameter of a circle and is a constant with a value of about 3.14159. To square something is to multiply it by itself. In the calculation below I have divided the diameter in mm by a thousand to get it in metres. The result is in cubic metres.

Typical water supply pipe: 3.14159 * (31.825 / 1000) * (31.825 / 1000) * 8000 / 4 = 6.3638 m ** 3
Light geothermal pipe: 3.14159 * (37.541 / 1000) * (37.541 / 1000) * 8000 / 4 = 8.8550 m ** 3

If we the divide the answers by 1000, the number of litres in a cubic metre we get:

Typical water supply pipe: 6364 li
Light geothermal pipe: 8855 li

The upper estimate agrees quite well with that of leau78 (8800 li) and ASA (9121 li) the lower estimate is very different however nearly two and a half thousand litres less!

PS: I usually get charged out at £45 per hour to answer questions like this.

Gosh, Tielhard thanks! What happens is the water is pumped out of the bore and into a 20,000 gallon tank. We then pump it out of there and it comes to the house and into a 5,000 gallon tank on top of a 40 foot stand (so that's were we get the pressure, Sue, it's not as good as a town supply but it's not too bad either) and when we think that is nearly full we have to race out to the bore and switch the motor off so it doesn't overflow much. There was no real reason that we wanted to kow how much water was in the pipe, just so we'd know how much was going to come out of the first tank before we'd actually start filling up the second, I suppose I hope that makes sense!

Eight k's was the nearest permanent water. We're lucky, our neighbours had to go fifteen k's.

Just send me the bill, Tielhard.

That is one heck of a 'back garden' you have there Jillian Just how many kilometers do you have to go to get off your land?

The house is pretty much up one end of the place so one way we're only 3km from the boundary and the most we'd go would be about 25km. Glad we don't have to mow it, eh?

Oh Jillian, this whole island is only about 14.5 kilometers by 8 kilometers - and we have nearly 90,000 people living here... and thirteen police forces ( had to get that one in!).

LOL, a friend once worked out that our place is as big as Greater London.

There is 90,000 people? I always thought of Jersey as being like a sleepy kind of holiday town! What do you mean by different police forces?

Oooh Jillian, you haven't done my quizzes! Actually I just gave away one of the answers This is probably the most highly policed places in the world and, with the possible exception of the Vatican, probably has the oldest police force too.

Monaco is somewhere in the running, you'd best not even think of entering with mismatched socks...or they'll see you!
Getting your car towed costs about 100 quid! The area is just under two square kilometres.
Four hundred officers work in Monaco. More than the entire city of Nice.

Oh so you mean 13 actual forces? I thiought it may havve meant 13 individuals! Is here a low crime rate? Seems no one would be game with that many police about!

The City of London, with an area of just over a square mile (2½ square kilometres) and a resident population of 5,500, has a police force of about 700 officers, i.e. about 1 cop to 8 residents.

Of course, the City has about half a million people within its boundaries during working hours. And since it's one of the world's great financial centres, the City Police also have to deal with a lot of financial fraud, i.e. they have to ensure that it's only carried out by properly educated Englishmen who speak with nice accents.

policing the pipes are very important.....
especially if they have water.