AIR FAILURE:
For valves you might use the following terms:
for vaccum valves this means
клапан (вентиль) не держит воздух (не держит по воздуху)
клапан (вентиль) "травит" ("травит воздух") = {профессиональный жаргон}

Since your context was not too complete, in case it is the diving equipment, this might also mean СБОЙ ДЫХАТЕЛЬНОГО АВТОМАТА

As for valves in heating systems which work with hot water or oberheated vapour, the same term sometimes means ВОЗДУШНАЯ ПРОБКА which means that the air bulbs stop the flow of heating liquid in pipes).

So, would you need additional info, pls give additional anfo as well:)

Yours,
Dr. Tagir S. Tagirov
KSU