Backflow preventer and relief valve assembly

• US 3,996,962 A
• Filed: 03/19/1976
• Issued: 12/14/1976
• Est. Priority Date: 03/19/1976
• Status: Expired due to Term

• Current Assignee: M&FC Holding, LLC (Xylem, Inc.)
• Original Assignee: Rockwell International Corporation
• Inventors: Sutherland, Ray
• Primary Examiner(s): Cohan, Alan
• Assistant Examiner(s): Michalsky, Gerald A.
• Application Number:
  US05/668,627
• Time in Patent Office: 270 Days
• Field of Search: 137/215, 137/527, 137/527.2, 137/527.4
• US Class Current: 137/527.4
• CPC Class Codes: E03C 1/106 using two or more check valves
• CPC Class Codes: E03C 1/108 having an aerating valve
• CPC Class Codes: F16K 1/2007 specially adapted operating means therefor operating means per se F16K31/00
• CPC Class Codes: F16K 1/2021 with a plurality of valve members
• CPC Class Codes: F16K 15/033 spring-loaded
• CPC Class Codes: F16K 15/035 with a plurality of valve members
• CPC Class Codes: F16K 2200/204 in series
• CPC Class Codes: Y10T 137/3149 Back flow prevention by vacuum breaking [e.g., anti-siphon devices]
• CPC Class Codes: Y10T 137/3331 With co-acting valve in liquid flow path
• CPC Class Codes: Y10T 137/7901 Valve head movably connected for accommodation to seat

Abstract

A backflow prevention assembly designed for connection between a main supply line and a service pipe in water supply service, comprising two check valves in series and a relief valve for draining the chamber between the two check valves under certain operating conditions.

Claims

1. A check valve assembly adapted to be mounted to accommodate horizontal fluid flow, having a housing and a valve assembly in said housing, comprising:

a valve seat in said housing defining a fluid flow passageway, a hinge member mounted on said housing for pivotal movement about an axis normal to the direction of fluid flow, a valve cover member carried by said hinge member adapted to cooperate with said valve seat to control fluid flow through said valve, link means pivotally attached at one end to said hinge member and projecting rearwardly from said cover member, the other end of said link member being pivotally mounted on a roller assembly which bears on a track, said roller assembly being spring biased to the valve closed position, said roller assembly being constrained to move in a vertical path by said track which is fixed to said housing, said link means making an acute angle with the horizontal when said valve assembly is in the closed position, whereby a large portion of the force tending to open said check valve is exerted against said track.

2. The check valve assembly of claim 1, wherein said valve cover member is pivotally mounted on said hinge member.

3. The check valve assembly of claim 1, wherein said hinge member pivot axis lies in the plane of said valve seat face.

4. The check valve assembly of claim 1, in which said housing has a cover member mounted thereon, said cover member providing a seat for said spring, and whereby said valve elements are available for servicing by removal of said cover member.

5. The check valve assembly of claim 1, wherein the angle said link means makes with the horizontal is approximately 30°

.

6. A check valve assembly adapted to be mounted to accommodate fluid flow having a housing and a valve assembly in said housing comprising:

a valve seat in said housing defining a fluid flow passageway, a valve cover mounted on said housing for pivotal movement about an axis normal to the direction of fluid flow and adapted to cooperate with said valve seat to control fluid flow through said valve, a track fixedly mounted to the rear of said valve cover extending in a direction normal to the pivot axis of said valve cover, a roller assembly mounted on said track for movement thereon, link means pivotally attached at one end to said valve cover and projecting rearwardly from said valve cover, the other end of said link means being pivotally mounted on said roller assembly, means biasing said roller assembly to the valve closed position, said link means making an acute angle with the horizontal when said valve assembly is in the closed position whereby a large portion of the force tending to open said check valve is exerted against said track.