Valve stem
SELF-CONTAINED VALVE WHICH OPENS TO ADMIT GAS TO A CHAMBER AND AUTOMATICALLY CLOSES TO PREVENT THE GAS FROM ESCAPING
Tire valves; Invisible tire valves; Valve stems; Valve stem (tire); Tyre valves; Tyre valve; Tire valve
A valve stem is a self-contained valve which opens to admit gas to a chamber (such as air to inflate a tire), and is then automatically closed and kept sealed by the pressure in the chamber, or a spring, or both, to prevent the gas from escaping. They are most commonly used on automobile, motorcycle, and bicycle tires, but also for many other applications.