BUTTERFLY TYPE VALVE WITH STRESS SEAL

• US 3,684,239 A
• Filed: 11/30/1970
• Issued: 08/15/1972
• Est. Priority Date: 11/30/1970
• Status: Expired due to Term

• Current Assignee: M&FC Holding, LLC (Xylem, Inc.)
• Original Assignee: Harry Schwartzbart, Robert Albert Douty
• Inventors: Schwartzbart, Harry, Douty, Robert Albert
• Primary Examiner(s): Weakley, Harold W.
• Application Number:
  US05/093,651
• Time in Patent Office: 624 Days
• Field of Search: 251/173,307
• US Class Current: 251/173
• CPC Class Codes: F16K 1/228 Movable sealing bodies

Abstract

A butterfly valve assembly wherein metal body has an annular seat member, peripherally engaged by a rotatable disc in valve closed position, the seat member is an annular metal band having thickened ends welded to the body providing a continuous pressure tight annular space between the band and the body, and fluid pressure preferably higher than line pressure is introduced into that space when the valve is closed for stressing the seat band to sealingly engage the disc.

Claims

1. In a butterfly type valve assembly for handling high temperature fluids, a metal body having a large diameter continuous annular internal groove of constant width, means rotatably mounting a closure disk within said body, means providing a continuous annular metal valve seat member within the body adapted for peripheral engagement with said disk in the valve closed position, and providing a substantially continuous annular space between said seat member and the body, and means for introducing fluid under pressure into said space to stress said seat member about the periphery of said disk to provide a fluid tight seal, said valve seat member consisting of a continuous uniform width band having thickened opposite ends forming parallel external ribs projecting around its outer periphery and welded to said body within said groove.

2. In the valve defined in claim 1, said body and seat member being metals having similar coefficients of expansion.

3. In the valve defined in claim 2, said body and seat members being composed of similar stainless steels.

4. In the valve defined in claim 1, the pressure in said space being appreciably higher than the lIne pressure within said body when the valve is closed.

5. In the valve defined in claim 4, first valve means controlling fluid communication between an external source of fluid pressure and said space, and means synchronized with movement of the valve closure member for opening said first valve means when the closure member is in valve closed position engagement with said seat member.

6. In the valve defined in claim 5, second valve means controlling fluid communication in a passage between said space and the interior of said body, and means synchronized with movement of said valve closure member for opening said second valve means when said valve closure member is in valve open position, while closing said first valve means when said space is in open communication with the interior of said valve body.