Leakage-free switching dual valve arrangement

摘要

A leakproof double seat valve comprises two slide-valve bodies (1, 2) in a valve housing (3) with conduit connections (4, 5). In the closed position, the two slide-valve bodies (1, 2), which can be actuated independently of one another, rest against valve seats (6, 7) in the valve housing (3) and are at a distance apart, thus forming a leakage cavity (8). During the opening process, the first slide-valve body (1) can be brought to rest against the other, second slide-valve body (2) before it leaves its valve seat (6), the former movement involving a reduction in the size of the leakage cavity (8). The second slide-valve body (2) is provided with a tubular extension (9) which is passed out of the valve housing (3) in a sealed manner and connects the leakage cavity (8) to the surroundings of the valve. In a double seat valve of this kind, optimum cleaning with minimum consumption of flushing agent is achieved by virtue of the fact that the two slide-valve bodies (1, 2) can each be moved independently of the other by a partial stroke in the opposite direction to that of opening into a flushing position in which the slide-valve body (1 or 2) is free of its valve seat (6 or 7) and rests against a housing stop (13 or 14) provided with openings (11 or 12) for flushing agent.