vent pipe

a pipe above a waste pipe or soil pipe that allows gas to escape from the system.

Origin of vent pipe

First recorded in 1855–60

Typical simple forms of vent-pipe suitable for acetylene apparatus are shown in Fig. 7.

Acetylene, The Principles Of Its Generation And Use |F. H. Leeds
The S trap is, upon the whole, the best, but it should be provided with a vent-pipe to prevent siphonage.

A System of Practical Medicine by American Authors, Vol. I |Various
No water enters the vent-pipe from the holder, and therefore no gurgling or irregular pressure is produced.

Acetylene, The Principles Of Its Generation And Use |F. H. Leeds
So tall a vent-pipe, however, seriously raises the centre of gravity of the bell and may make it top-heavy.

Acetylene, The Principles Of Its Generation And Use |F. H. Leeds

It is indispensable that every acetylene apparatus shall be fitted with a safety-valve, or more correctly speaking a vent-pipe.

Acetylene, The Principles Of Its Generation And Use |F. H. Leeds