Electric Vacuum Valve

electric
(of a situation) exceptionally tense; "an atmosphere electric with suspicion"
using or providing or producing or transmitting or operated by electricity; "electric current"; "electric wiring"; "electrical appliances"; "an electrical storm"
a car that is powered by electricity
An electric train or other vehicle

vacuum
A space entirely devoid of matter
A space or container from which the air has been completely or partly removed
the absence of matter
void: an empty area or space; "the huge desert voids"; "the emptiness of outer space"; "without their support he'll be ruling in a vacuum"
A gap left by the loss, death, or departure of someone or something formerly playing a significant part in a situation or activity
clean with a vacuum cleaner; "vacuum the carpets"

valve
a structure in a hollow organ (like the heart) with a flap to insure one-way flow of fluid through it
A cylindrical mechanism in a brass instrument that, when depressed or turned, admits air into different sections of tubing and so extends the range of available notes
device in a brass wind instrument for varying the length of the air column to alter the pitch of a tone
A device for controlling the passage of fluid through a pipe or duct, esp. an automatic device allowing movement in one direction only
A membranous fold in a hollow organ or tubular structure, such as a blood vessel or the digestive tract, that maintains the flow of the contents in one direction by closing in response to any pressure from reverse flow
control consisting of a mechanical device for controlling the flow of a fluid