Valve stem
Valve stem

Schrader valves (also called American valves) consist of a valve stem into which a poppet valve is threaded with a spring attached. They are used on virtually all automobile tires, and in the United States, on most wider rimmed bicycle tires. In addition to tires, Schrader valves of varying diameters are used in refrigeration and air conditioning systems, plumbing, fuel injection engines, suspension systems, and SCUBA regulators, allowing the user to remove and attach the hose while in use. Another use for Schrader valves is in the fuel injector rail of many automobiles, where it is used as a quick and easy point to check fuel pressure and to connect a cleaner injection device or cleaner cartridge.

Presta valves (also called Sclaverand valves or French valves) are normally only used on bicycles. The stem has a narrower diameter (nominally 6 mm) than the thinnest (nominally 8 mm) Schrader type, and so the bore of the hole in the rim through which the stem passes can be smaller.

Many other valves exist that are used only in certain regions or for limited purposes.

For example the "Regina Valve" is a valve very much similar to the Presta and mostly being used in Italy. Invisible tire valves are different in design from traditional tire valves. An inflator stem is not used; instead, a removable cap on a valve stem embedded in the tire rim is fitted, with only the cap visible. When inflating the tire, the cap is first removed, typically with a coin, and then a "portable" dedicated inflator stem is screwed onto the valve stem. Through the inflator the tire is inflated as usual. http://www.gdgee.com/valve-accessories-and-valves/valve-stem-of-ball-valve-series-6308.html


valve stem