| 摘要 |
PURPOSE: A seat assembly for keeping airtightness is provided to minimize leakage of a fluid due to the inlet of foreign materials and abrasion in a face contacting with an opening and shutting ball by improving a structure. CONSTITUTION: An opening and shutting ball(10) received in a ball valve body(1) and having a fluid hole(2) is interposed between a shaft receiving portion(3) and a stem(4). A pair of caps(5) is fixed on both sides of the ball valve body. A seat ring(50) moves rectilinearly. A solid pillar drive seat(53) made of an abrasion resistant material slides on a reduced circumferential end(52) of the seat ring. A seat spring(51) pressurizes the opening and shutting ball. At least a pairs of O rings(55-58) are placed on the solid pillar drive seat and on the circumference of the seat ring. A hydraulic ring groove(60) for hydraulic operation is formed between the contacting faces of the seat ring and the solid pillar seat. A fluid is communicated to the hydraulic ring groove via an operation hydraulic pressure inlet conduit(70). According to simultaneous or sequential application of elasticity and hydraulic pressure on the opening and shutting ball, airtightness is enhanced.
|
