| 摘要 |
A normally-closed valve comprises a valve housing 315 ( the valve member formed of an upper and lower portion 3113, 3116) with a cavity 390, in which is an elastomeric spring 318. The spring may be formed of one of the following; rubber (natural or synthetic), Viton®, butyl rubber, silicone or neoprene. The upper portion 3113 comprises a stem portion 311, through which there extends a passageway 3112 for dispensing material. When the valve is actuated the elastomeric spring 318 is compressed, allowing the upper and lower portions (3113, 3116) of the valve to move downwards. The stem inlet 3114 passes through the stem-sealing gasket 313 and the stem inlet 3114 enters the cavity 390, allowing material to be dispensed via the inlet hole 400 at the base of the valve. A through channel may be present through the elastomeric spring 318 to act as a path for material to be dispensed from below the valve to the stem passageway 3112. The spring 318 may be formed of the same material as the stem-sealing gasket 313. |
