Abstract: A device in a valve (1) includes a valve housing (2) with at least a first (3) and a second (4) fluid port. A closure element (5) including a sealing portion (15) and diaphragm (30) is arranged in the valve housing (2). The sealing portion (15) is movable between an open position and a closed position. The closure element (5) and valve housing (2) form a flow passage (11) which communicates with the fluid ports when the sealing portion (15) leaves the closed position. A second sealing portion (14) is arranged in contact with a support portion (25) of the valve housing (2). An abutment element (16) is arranged in contact with the second sealing portion (14). The abutment element (16) transmits a force via the second sealing portion (14) toward the support portion (25) to provide a seal. The force is at least partly exerted by a spring element.