First: to act as an automatic non-return valve by preventing a backflow of steam from the mainsteamheader 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。
2
When more than one boiler is connected to the mainsteamheader, a stop check valve should be installed in the pipeline between each boiler and the header.