I was sitting in the conservatory of the Hillborough Hotel the other night looking over the lovely view of the Gasometer and I started to wondering (as one does after a few pints) how they work.

They telescope up and down but there has to be a seal between each section. My best guess was that each section is double walled and the cavity between was filled with water and the section above floated on it somehow.

Anyone know? It’s a little sad I realise but it really has been bugging me.
:help:

The pressure must be huge inside them to lift the top up because they look like they are made from realy heavy thick iron/steel.

Found this : http://www.cse.polyu.edu.hk/~cecspoon/lwbt/Case_Studies/Gasometer_City/Gasometer_City.htm

while looking for the answer

I would have thought that the pressure inside would be quite low and it would be the basis for local domestic gas pressure. Maybe the height of the things are held up by a large screw or weight counterbalance rather than purely the gas at pressure.

But I would love to know..

Found this : http://www.cse.polyu.edu.hk/~cecspo...ometer_City.htm

I found that too, while doing the same thing. It's amazing isn't it :)

Originally posted by Fearful
I found that too, while doing the same thing. It's amazing isn't it :)

Yeah, thats what I call inner-city redevelopment.

no-one in the uk would have the balls to do that would they!!!

They would just get blown-up here.

Whats amazing is how beautifull a functional boring thing like a gassometer could be in the 19th century.

A bit of clue as to how they work though in the description of the building "Above a 1.7 m deep foundation of concrete, sits a 12m high ring of brickwork with an internal diameter of 62.8m, which forms the walls to the water tank."

So water is involved somewhere.

The gassometers near St Pancras station where nice to look at but they have gone now.

Originally posted by muddycoffee
I would have thought that the pressure inside would be quite low and it would be the basis for local domestic gas pressure. Maybe the height of the things are held up by a large screw or weight counterbalance rather than purely the gas at pressure.

But I would love to know..

Gas pressure is regulated depending on where it is and there are a series of regulators to reduce pressure as it goes from supplier to the grid under the street, and from the grid to the user.

Gas pressure can start out quite high as you'd imagine but when it goes through a high pressure regulator it is lowered to no higher than 7 Bars. Further along the pipework it will then meet an Intermediate pressure regulator which will lower it again to no higher than 2 Bars. This is the kind of gas pressure you'd find if you dug up the gas pipes in the street. When it gets close to a property it goes through a medium pressure regulator which will lower it to approx 75 millibars and then it will travel to the gas meter in the property which will finally lower it to no higher than approx 24 mbars.

I'm not sure how the gasometers (if that's their real name) work as I only work domestic. Maybe I'll find out one day as someone at work will probably know. :)

I am really surprised I couldn't find a webpage to show the basic engineering.
I have made some basic sketches which you can see here (http://i2.photobucket.com/albums/y28/cgksheff/Sheffield%20Forum/gasometer05.jpg) .

A very simple description is like this:
Imagine an upturned can with an interlocking lip that is sitting in a tank of water and pipe the gas in.
As the gas increases, the cup rises and then picks up the overturned lip of the next cylinder. The lips hold a channel of water and so form a seal.
And so with the next cylinder.

It is really much more complicated than that and mechanisms are in place to ensure that when it is coming down, the outer cylinders fall first.
There are counterweight systems to help move the cylinders and to increase pressure if needed.
Keeping the whole thing warm in winter was also needed to prevent freezing of the water in the lips which would have broken the seals.

cgksheff
thanks very much those are excellent diagrams. You have explained it very well, and now another bit of bizarre engineering is un tangled.