All pipe lines, valves, and nozzles shall be isolated from the atmosphere by a blank, pipe cap, or plug when not being used.

当不在操作使用时，所有管线、阀门、和喷嘴应用盲板、管帽、或塞子使其和大气隔开。

youdao

Nomatter transporting gas or oil, there are pipelines, there are pipe fittings such as bend pipe, reducing joint, T-pipe, pipe cap and so on.

无论是用管道输气、输油，凡有管道的地方，都少不了弯头、异径接头、三通、管帽等管件。

youdao

Pipe series: Elbow, tee, cross, movable joint, Bu core, reducer, pipe cap, choke plug, inside the wire, outside the wire, turned-over edge, increaser etc.

管件类： 弯头、三通、四通、活接头、卜芯、大小头、管帽、堵头、内丝、外丝、翻边、异径管。

youdao

Crews then turned to placing a cap over the pipe -- not to stop it, but to direct at least some of the oil to ships on the surface.

VOA: special.2010.06.04

Yes: baseball, sitting over there with its wool cap and its smelly pipe.

WSJ: NBA, NHL Playoffs: Why Are the Playoffs So Long?

Specifically referring to the Comcast 250GB limit that has recently come under fire from Netflix and others now that its Xfinity TV app on Xbox 360 skirts the cap entirely, Aragon noted cable companies have the pipe and the bandwidth and can restrict competing services.

ENGADGET: Sony exec confirms IPTV aspirations, says they're on hold due to bandwidth caps