摘要 |
A stroke-action valve has on both sides of a narrow duct cross-section F preferably an annular groove connected with one of the connection chambers 2 a first and a second valve seat 6, 7. A closure element 8 co-operates with both valve seats 6, 7 and contains openings 18 which provide communication between zones 16, 17. The two zones 16, 17 ie next to the side of the two valve seats 6, 7 opposite to the narrow duct cross-section F are connected with the other connection chamber 3. In this way, even small lengths of stroke of the stroke-action valve permit the passage of relatively large flow quantities. Seal 13 has lips 14, 15 which co-operate with the seats and the seats may be offset for non-simultaneous closure. A further embodiment (figure 2) includes a leakage detection device in the form of a rotor (130) and an electro-optical pulse measuring component (133) and a device which measures the stroke of the valve closure element (108). |