| 摘要 |
PURPOSE:To prevent the life of a cylindrical valve unit from being shortened due to wear, by alternately piling up a plurality of sealing rings and a plurality of coupling rings on each other and clamping them together to form a cylindrical body. CONSTITUTION:Sealing rings 3, 3a-3d and coupling rings 4, 4a-4d are alternately piled up between clamping rings 1, 2. These piled-up elements are secured together by assembly bolts 5 extending through lobes 2a provided at the same interval on the peripheral surfaces of the clamping rings 1, 2, so that a cylindrical body 6 is formed. As a result, a sealing member does not need to be secured at the side of a piston valve and they are brought into contact with each other only in the stopped position of the piston valve. For that reason, wear under motion is prevented, so that the life is kept from being shortened due to the wear. |
