Double seat valve

Abstract

The invention relates to a double seat valve, which is capable of cleaning the seat and which is improved compared to that of the prior art, whereby a delivery as free from turbulence as possible of the seat cleaning flow into and out of a leakage cavity is ensured, and a pressure-increasing direct action upon the seat areas is reliably prevented. This is achieved in that: a second closing element (4), when in its closed position, rests with a stopping surface (4e), which is placed on an end face of its cylindrical projection (4*), upon a transition interface (2e, 2e*) and, to be precise, directly upon a first seat face (2a, 2g) in an adjoining manner; in the end face of a second cylindrical projection (4*), a central recess (4d) is provided which, radially outside, starts (a starting point of a contour (K)) with a rotationally symmetric reversing surface (4b) and is delimited on an end side by an end face (4c) oriented, in essence, essentially perpendicular to a longitudinal axis of the second closing element (4), the reversing surface (4b) leading into the end face (4c) (a leading point of the contour (K)) ; the reversing surface (4b) and the stopping surface (4e) form a second wraparound edge (U2) that, when the second closing element (4) is closed, directly abuts against a first end section (2g) of the first seat face (2a); when viewing a meridian section, the reversing surface (4b) has the contour (K) with a bend-free curve, a direction vector in the leading point of the reversing surface (4b) points into a discharge borehole (3d) centrally provided in a first closing element (3) without colliding with the first closing element (3) in the vicinity of its areas bordering a leakage cavity (5) or of a middle seal (8, 8*) and forming dynamic pressure, and an end side delimitation of the first closing element (3) facing the leakage cavity (5) is at an axial safe distance (x) from a direction vector on an outlet point of the transition interface (2e) into the first end section (2g).

Description

technical field [0001] The invention relates to a double-seat valve comprising two closing parts arranged in series and movable relative to one another. Background technique [0002] A double-seat valve of this type is known from DE 196 08 792 C2, which is also known as a can Double-seat valves with clean seats. In the known double-seat valve, each of the three sealing rings involves a separate sealing ring, each of which has only a single function. The first sealing ring in the first closing part is a purely radially acting sealing ring, which slides in the first valve seat surface designed as a cylindrical outer peripheral surface and due to the set bias (slidingly engaged sealing ring) And play a sealing role there. The second sealing ring on the second closing part or acts on the second seat surface of the conical design, and is called the axial / radial acting sealing ring (to compress the sealing ring), Alternatively, a purely radially acting sealing ring (sliding s...

AI Technical Summary

Problems solved by technology

If the pure throttling gap effect is considered, it is equivalent to reconfigure the throttling gap from a position on the side of the leak chamber to a position away from the leak chamber, however, this modification makes when the second closing part is transferred to its valve Cleaning critical condition for the first seat seal in the first closing part in the seat cleaning position

In this case, there is the risk that at least a part of the second seat cleaning fluid will directly hit the sealing area of ​​the first closing part, since there is no upstream, shielding first seat seal cylindrical protrusion forming the throttle gap

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