| 摘要 |
The invention relates to a double seat valve comprising two valve closure members (8,9) guided in a valve housing (11) for coaxial movement relative to each other and to respective coaxial valve seats (3a,3b) between an open position and a closed position, realising together in their closed position a double seal one of said closure members (8) being adapted to abut during opening movement against the other closure member (9) for moving same also into its open position, a leakage space (7) between said closure members (8,9) being permanently connected to the outside of the valve, one closure member being a side piston (8) having radial sealing means (4) cooperating with a cylindrical valve seat (3b), the other closure member (9) having a recess (10) adapted to sealingly receive during opening movement the end portion of said slide piston (8), said cylindrical valve seat (3b) or the cylindrical seat wall (10a) of said recess (10) having an annular groove (10b) permitting in an intermediate position of said radial sealing means (4) a seat-cleaning flow of liquid along said cylindrical valve seat (3b) and between the circumferential surfaces of said radial sealing means (4) and said annular groove (10b). |
