Plastic ball valve stem seal

• US 5,232,201 A
• Filed: 01/07/1992
• Issued: 08/03/1993
• Est. Priority Date: 01/07/1992
• Status: Expired due to Term

• Current Assignee: Flowserve Management Company (Flowserve Corporation)
• Original Assignee: M&FC Holding, LLC (Xylem, Inc.)
• Inventors: Sears, Frank D., Spears, Ricky E., Horvath, Stephen M.
• Primary Examiner(s): Fox, John C.
• Application Number:
  US07/817,698
• Time in Patent Office: 574 Days
• Field of Search: 251/214, 251/315
• US Class Current: 251/315.01
• CPC Class Codes: F16K 5/0689 between housing and plug

Abstract

A plastic ball valve having improved valve stem sealing means.

Claims

1. In a ball valve comprising a valve body, conduit portions extending from said valve body, said valve body having a chamber therein, said conduit portions defining a flow passageway therein extending through said chamber, said valve body having a bore therein normal to said flow passageway, a ball member disposed in said chamber and movable between closed and open positions in said flow passageway, and a valve stem disposed in said bore and connected to said ball member, and improvement comprising a flange extending radially outwardly from said valve stem and disposed in said chamber, an elastomeric sealing ring disposed around said valve stem, abutting said valve stem, abutting a surface of said flange, and disposed in an annular groove in a wall of said bore, a handle mounted on said valve and having a portion of said valve stem in a central opening extending through said handle, and a screw disposed in said central opening and threadedly engaged with said valve stem, whereby upon rotation of said screw said valve stem is caused to move in a direction outwardly from said chamber and said flange is caused to move in a direction toward said sealing ring to compress said sealing ring axially of said stem and expand said sealing ring radially of said stem to effect a tight seal in said groove to prevent leakage about said stem from said chamber, said screw being disposed in a recess in a top surface of said handle, said handle being of a plastic material, and further including a plug of plastic material disposed in said recess and fused to said handle to permanently closed said recess, whereby to isolate said screw from the environment and from tampering.