To blow off

to let steam escape through a passage provided for the purpose; as, the engine or steamer is blowing off.
to empty (a boiler) of water through the blow-off pipe, while under steam pressure; also, to eject (steam, water, sediment, etc.) from a boiler.

See also: Blow, Blow

Webster's Revised Unabridged Dictionary, published 1913 by G. & C. Merriam Co.
References in classic literature ?
Only now did Pierre realize the full strength of life in man and the saving power he has of transferring his attention from one thing to another, which is like the safety valve of a boiler that allows superfluous steam to blow off when the pressure exceeds a certain limit.
"Man Alan," said I, "ye are neither very wise nor very Christian to blow off so many words of anger.
In your January article, "ILS Nuances Redux," you shouldn't be too quick to blow off ILS/LOCIAP step-downs as being for localizer only.
About three or four times a year, my wife and I climb up on the roof of our house to blow off the leaves and pine needles that have accumulated, and as long as we're up there, clean our skylights.
The system is simple, efficient, uses few parts, reduces Labor and improves air quality in the plant by eliminating the need for employees to blow off parts with hand held air nozzles.
Well I got to wondering, just how much smokeless powder would it take to blow off a person's face when the bomb isn't contained by anything other than the tobacco leaf wrapper on a cigar?
This thoroughly appealing audiobook examines those daily irritations that make us want to punch someone and shows how actual people have chosen to find safe, legal, creative ways to blow off steam and get even besides.
106) says that fungal sprays could kill nontarget insect species, "but most of those species people don't want anyway." That is a flippant way to blow off reasonable questions.
The canopy jettison handle sits forward of the copilot gunner window (CPG) under a quick release panel for the ground crew to blow off the side panels in an emergency evacuation.
One is to blow off steam, get rid of that extra energy; the other is to get entangled but not with the same person you pick for fun!
Sumire is prickly, but likable; she feels trapped in a situation where she needs to marry a man who's smarter, richer and taller than her, and having Momo as a pet allows her to blow off steam.
As one possible explanation, he suggests hydrocarbons seeping upward along cracks in the seafloor might have collected under some impermeable barrier until pressure forced the buoyant gas to blow off its cover.