| 摘要 |
<p>Expansion chambers are connected at intervals along an oil filled cable to allow the maintenance of a preset pressure during temp. variations caused by load and weather conditions. The pressure is kept sensibly constant by a gas in the expansion chamber, separated from the oil by a diaphragm. For the diaphragm to be proof against diffusion of gas through it and into the oil, it is pref. made of metal. To give the required flexibility the metal sheet is deformed such that it can expand in two preferred directions. This can be done by six sided indentations (21) in the diaphragm material (20). The diaphragm is pref. in the form of a hemisphere, fixed inside a container, with oil on one side and gas on the other.</p> |
