First: to act as an automatic non-return valve by preventing a backflow of steam from the main steam header to the boiler.

首先，能过作为一个自动逆止阀，防止蒸汽从主蒸汽加热器上倒流到锅炉里。

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When more than one boiler is connected to the main steam header, a stop check valve should be installed in the pipeline between each boiler and the header.

如果连接主蒸汽热水器的锅炉不止一个，则在每个锅炉与热水器之间的管路上都应该安装一个截止止回阀。

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