PURPOSE: To prevent pollution based on particulates positively by providing a first bellows, provided expandably between a valve casing and a supporting member, for covering a valve stem fluid-tightly, and a second bellows, provided expandably between a valve body and the valve stem, for covering link mechanism between the valve body and valve stem fluid-tightly.
CONSTITUTION: A valve casing 1 is provided with a body 2 and a lid body 3, and a valve chamber 4 and a passage 5 are formed at the body 2. A valve stem 11 passes through the lid 3 and is hung down in the valve chamber 4, and the lower end of the valve stem 11 pierces the upper side wall of a supporting member 12. A first bellows 24 is expandably provided between the valve casing 1 and supporting member 12, covering the valve stem 11 fluid- tightly. Link mechanism for linking the valve stem 11 with the supporting member 12 is provided with a valve body 13, and a second bellows 25 is expandably provided between the valve body 13 and supporting member 12, covering the link mechanism fluid-tightly. Accordingly, even if particulates are generated, their leakage into the valve chamber 4 is prevented, so that pollution by particulates is prevented.
| JP4002906 | Open / close valve |
| WO/2011/153562 | VACUUM VALVE |
| WO/2009/080304 | GATE VALVE FOR A VACUUM CHAMBER AND VACUUM CHAMBER |
SUGANO YOICHI
UCHISAWA OSAMU
