2007-12-21 19:35:41 · 7 answers · asked by Anonymous in Science & Mathematics ➔ Physics
Because of the amount of stored gas in them, or not, in the case of them being down!
2007-12-21 19:39:13 · answer #1 · answered by Sal*UK 7 · 4⤊ 0⤋
Because essentially gas towers are just like balloons, but made of metal instead of rubber. When gas is pumped in, the pressure increases and forces the tower to rise (like the balloon expanding) and as the town uses up some of the gas, the pressure inside the tower drops, so there is nothing to stop the tower sinking back down under its own weight of metal (ie contracting, or the balloon deflating). So more gas is pumped in.
Care has to be taken not to put too much gas in, or the tower could rupture (just like overinflating and popping a balloon). Thats why there was an operator taking readings at the tower in Colin M's reply above.
2007-12-25 16:30:10 · answer #2 · answered by dontknoweither 4 · 0⤊ 0⤋
The more correct term is gasometer.
They move up and down because the pressure of gas has to be maintained to your appliances, this means that in low usage times they are pumped up, as described above then in high usage they come down as the extra gas is used up.
Try: http://en.wikipedia.org/wiki/Gasometer
Hope that helps.
2007-12-25 17:15:27 · answer #3 · answered by jmb944 2 · 0⤊ 0⤋
They're basically upside down cans, floating on a liquid base that provides the seal. They rise when they contain more gas, sink when the volume goes down. A remarkably simple & effective invention.
There used to be one at our gasworks (now gone), the operator was provided with a spotlight and telescope so he could read the markings on the side of it and twiddle his valves accordingly.
2007-12-22 03:52:49 · answer #4 · answered by champer 7 · 4⤊ 0⤋
They are placed on big chambers of water which allows them to go up and down depending on the amount of gas in them to mantain the pressure required.
2007-12-22 08:28:28 · answer #5 · answered by Anonymous · 0⤊ 0⤋
To allow for the change in Gas quantities.
They are sat on a liquid base to keep constant pressure.
2007-12-22 03:39:18 · answer #6 · answered by Dr. 2 · 3⤊ 0⤋
They have gas. They strain (up), fart, then relax (down).
Sorry.. sometimes the dumb answers just have to be given. v.v
2007-12-22 03:43:50 · answer #7 · answered by Lunatic 3 · 0⤊ 4⤋