An aerosol powder valve has a valve housing, a valve body with an upstanding valve stem, radial stem orifices, and an annular tight-fitting gasket with a central opening forming the sole seal for the stem orifices. The valve stem is straight-sided above and below the stem orifices and is characterized...http://www.google.fr/patents/US5975378?utm_source=gb-gplus-shareBrevet US5975378 - Aerosol powder valve
