Valves and valve actuation – Rotary valves – Ball valve
Reexamination Certificate
1999-07-16
2001-02-13
Shaver, Kevin (Department: 3754)
Valves and valve actuation
Rotary valves
Ball valve
C251S317000
Reexamination Certificate
active
06186476
ABSTRACT:
BACKGROUND OF THE INVENTION
The invention relates to a shut-off valve for pipelines and/or for tanks that hold liquids.
A shut-off valve for pipelines and for tanks that hold liquids is already known which is fitted with a closure element and with a passage borehole positioned crosswise to the axis of oscillation of the closure element for purposes of opening and closing the entire free flow area (DE 44 09 796). At the height of the flow area, crosswise to the longitudinal axis, the closure element is configured free of material towards one side. The remaining outer wall of the closure element facing the opposite side forms the sealing surface area of the free flow area along the flow axis. The spherical closure element is completely surrounded by two sealing half shells, except for the flow area. The closure element is supported in these half shells in such a way that it can slide and rotate. The two closure elements are held together by the divided housing and by appropriate screws.
BRIEF SUMMARY OF THE INVENTION
The invention has the objective of creating a shut-off valve of the type described above and configuring it so as to ensure flawless sealing, even when cleaning liquids are used, which can have a very high temperature, or when sterile steam is employed.
This objective is achieved by the provision of a shut-off valve for pipelines and/or for tanks that hold liquids, whereby the shut-off valve has a two-part valve housing with a passage opening in which there is likewise a sliding and/or rotatably supported spherical closure element that has a passage opening and that is surrounded by two half-shell shaped sealing shells that form a passage opening that corresponds to the passage opening of the closure element. The sealing shells consist of a softer or more elastic material in comparison to the closure element. According to a primary feature of the invention, the sealing shells have an insert that is configured as a support element and that extends into the area of a first flange of the sealing shells and/or of the passage opening and the insert or support element projects from the sealing shells and forms a second flange that is associated with the first flange. Other feature of the invention will be described below. The As a result of the advantageous configuration of the shut-off valve and of the two sealing shells that are connected to each other, the sealing effect by means of the closure element is considerably improved and, at the same time, it is ensured that, even when the shut-off valve has been in operation for extended periods, it can be cleaned within a very short time without this impairing the quality of the closure device. Since at least the sealing shells are provided with an element or with a flange part that can be inserted into a recess of the valve housing, the two sealing shells can easily be pressed against the surface of the closure element as well as against the inner surface of the valve housing, thus achieving an excellent sealing effect between the closure element and the valve housing with just a few components.
A considerable improvement is achieved in that the sealing shells are fitted with an insert that can be made, for instance, of metal or of a steel alloy. This insert can be shaped like a shell and can be approximately fitted to the spherical inner surface of the sealing shell.
The insert can be designed as a support element while the sealing shell can be designed as an arched segment and can then be placed with one part into the area of one of the flanges provided on the sealing shell or into the edge area. It is also possible for the flange provided on the sealing shell to be of the same size and length as the flange provided on the support element. The two flange parts can either lie against each other loosely or else they can be firmly attached to each other.
For this purpose, it is advantageous for the sealing shell to likewise be made of an elastic or elastomeric material, so that it is readily fitted to the outer contour of the closure element or to the inner surface of the seat of the sealing shell. By using the support element, the closure element can withstand extreme stresses as well as high flow rates without the closure element being subsequently deformed or pulled out of its seat.
In order to attain sufficient pretensioning, it is advantageous for the inner diameter of both sealing shells—when they are joined—to be somewhat smaller than the outer diameter of the seat of the closure element. In this manner, sufficient surface pressure is achieved between the closure element and the sealing shells when they are assembled. By the same token, it is also possible for the width of the two flanges of the sealing shell—when they are joined—to be somewhat larger than the recess in the valve housing. This brings about the necessary pretensioning and surface pressure between the sealing element and the sealing shells when the valve housing is joined by means of the appropriate connecting screws.
An additional improvement can be achieved in that locking rings or O-rings are placed into corresponding recesses in the sealing shells and said rings additionally press the sealing shells against the surface of the sealing element.
In an advantageous manner, the sealing rings can be configured so as to be springy. Moreover, they can be designed as continuous or one-piece rings or else as split rings and can be made of a non-stick material, for example, of PTFE sold under the trademark TEFLON® or acetal, sold under the trademark DELRIN®. By the same token, the sealing shells can also be made of this material. As a result, the sliding capacity between the sealing element and the sealing shells is greatly improved. In addition, the surface of the sealing shell or the surface of the seat of the sealing shell in the valve housing can be provided with an appropriate lubricant and thus can ensure flawless, smooth turning of the closure element in the valve housing, but without impairing the sealing ability.
Furthermore, it is also possible to design the sealing shells without support elements whereby, in order to avoid a deformation of the sealing shells at high stress levels, the sealing shells are then made of a harder material than what is used for sealing shells with support elements. The sealing shells can be made of an elastomeric or rubber-like material. For this purpose, it is advantageous if the support element is vulcanized into the sealing shells or permanently integrated into the sealing shells.
Additional advantages and details of the invention are explained in the patent claims and in the description and illustrated in the figures. The following is shown:
REFERENCES:
patent: 3056576 (1962-10-01), Kulisek
patent: 3227174 (1966-01-01), Yost
patent: 3244398 (1966-04-01), Scarmamucci
patent: 3334650 (1967-08-01), Lowery et al.
patent: 3336938 (1967-08-01), Schenck, Jr.
patent: 3367359 (1968-02-01), Johnson
patent: 4696323 (1987-09-01), Iff
patent: 17 95 531 (1959-09-01), None
patent: 18 04 604 (1970-05-01), None
patent: 44 09 796 (1995-06-01), None
patent: 44 14 716 (1995-07-01), None
patent: 1 293 381 (1972-10-01), None
Brueggemann Mario Enrico
Goldsweer Karl Wilhelm
Browdy and Neimark
Goldsweer Karl Wilhelm
Keasel Eric
Shaver Kevin
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