If the exhaust system is under a vacuum, the casing must be warmed by gradually introducing the steam, after opening the exhaust valve.

如果排气系统处于真空下，必须在打开排气阀后，逐渐引蒸汽来加热壳体。

youdao

A forcible stream of air, gas, or steam from an opening, especially one in a blast furnace to aid combustion.

吹风，送风从出口，尤其是从助燃鼓风炉的出口出来的空气，其他气体或蒸汽气流。

youdao

The steam turbine drivers are warmed by slowly opening the exhaust valves.

汽轮机驱动器通过缓慢打开排气阀加热。

youdao

He was also the sovereign who offered to send some of his elephants to the United States, where he believed they would do a better job than steam engines in opening up the country for settlement.

BBC: No white elephants in this herd

The showiest is Dartmeet, a spacious beige suite that has an almost equally capacious bathroom featuring an immense rectangular tub, sauna, steam room, and French doors opening to a river-view terrace.

FORBES: Weekend in the Country

The opening date for an extension to a volunteer steam railway in Sussex has been announced.

BBC: Bluebell Railway extension opening date announced