Meaning of VALVE in English

[noun] [C] - a device which allows air or liquid to enter, or be prevented from entering, a container, or a similar structure in the human body, esp. the heart and the veins, that controls the flow of liquid, esp. bloodThe nuclear reactor was briefly shut down after an escape of non-radioactive steam from a faulty valve.The valve failed to open/close.On-shore oil fields are often built with emergency valves below ground level, to shut off the supply if a well gets out of control.If the No. 3 hydraulic line became ruptured, a shut-down/shut-off valve would automatically close.It was a weak heart valve that caused her death.A valve is also part of a musical instrument such as a trumpet which changes the sound by controlling the flow of air.

Cambridge English vocab.      Кембриджский английский словарь.