If you smell gas or see a broken line, shut off the main valve from the outside.

如果闻到煤气味儿，或看到管道破裂，要关掉从外面进屋煤气管道的主阀门。

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Residents are forbidden to use water to wash down paths and pavements, or to use a hose without an automatic shut-off valve.

禁止居民用水清洗道路和人行道，或使用没有自动断阀装置的水龙头。

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Intercept the fluid medium upstream of the valve to be inspected with a shut-off valve and ensure that the subject valve is not under pressure (vent downstream, if necessary).

截取阀门上游的流体介质，用一个关闭阀门来进行检测，确保相关的阀门不处在压力下(如果必要的话，排除下游的流体介质)。

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Safe to say that the Department of Defense does not have a submersible with arms to shut off the valve of a deep-water oil well.

WHITEHOUSE: Aboard Air Force One En Route Andrews Air Force Base

That starts off with a "junk shot, " in which material such as rubber tires and golf balls is pumped into the shut-off valve, or blowout preventer, that sits atop the well.

WSJ: Spill Fight Shows Progress