A valve immediately shuts off the gas when the lid is closed.

当盖子合上时，立刻会有一个阀门切断煤气。

《牛津词典》

If you smell gas, shut off the main gas valve.

如果你闻到煤气味，关闭总阀门。

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Leave the gas on at the main valve, unless you smell gas or think it \ 's leaking.

除非闻到煤气味或认为煤气正在泄漏，不用关掉煤气阀门。

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So the Joule free expansion involves opening this valve and asking what happens when this gas moves into the other bulb or distributes between the two.

焦耳自由膨胀就是,打开阀门后的过程,气体从一个腔跑到另一个腔,并在它们之间平均分配。

麻省理工公开课 - 热力学与动力学课程节选

Though a program displays panels showing all the critical processes of a real rig (fire and gas detectors, valve status, oil flow from the sea bed and so on), and then responds to the actions of the trainee by altering these displays appropriately, a human operator can intervene at any time if things seem to be going too smoothly.

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"The absence of the valve and regulator would explain how such a large volume of gas would be released into the home, " Curry told CNN.

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Mike Schaffner directs information technology for the Valve and Measurement Group of oil and gas products and services company Cameron in Houston.

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