Diaphragm valve

• US 5,485,984 A
• Filed: 05/27/1994
• Issued: 01/23/1996
• Est. Priority Date: 06/02/1993
• Status: Expired due to Term

• Current Assignee: Masako Kiyohara
• Original Assignee: Masako Kiyohara
• Inventors: Yamaji, Michio, Kojima, Tetsuya, Itoi, Shigeru
• Primary Examiner(s): Schwadron, Martin P.
• Assistant Examiner(s): Lee, Kevin L.
• Application Number:
  US08/250,609
• Time in Patent Office: 606 Days
• Field of Search: 251/331, 251/363, 251/63.5, 251/118, 251/359, 251/360, 251/361, 251/362
• US Class Current: 251/331
• CPC Class Codes: F16K 7/16 the diaphragm being mechanically actuated, e.g. by screw-spindle or cam

Abstract

A diaphragm valve is provided with a removable metallic elastic seating ring (7) having a first passage (10) and at least one second passage (11) extending through it. The first passage communicates with an inlet passage (8) of the valve while the second passage communicates with the outflow passage (9). A first surface (7a) of the seating ring is provided with a valve seat (12) against which the diaphragm (6) may be pressed to block fluid flow through the valve. A second surface (7b) of the seating ring has two annular and axially extending projections (15, 16). The first projection (15) contacts a bottom surface (2a) of valve chamber (2) in a region surrounding the opening where the inflow passage joins the valve chamber. The second projection (16) contacts the bottom surface of the valve chamber around the periphery of the valve chamber. The first projection extends axially of the seating ring to a slightly greater extent than the second projection so that when a diaphragm holder ( 5) presses the diaphragm against the periphery of the seating ring, the seating ring flexes thus causing increased contact pressure between the first projection and the bottom surface of the valve chamber. This reduces the possibility of leakage flow between the bottom wall and the seating ring from the inflow passage to the outflow passage.

Claims

1. A diaphragm valve comprising:

a valve body having a chamber, a fluid inlet passage and a fluid outlet passage communicating with said chamber through openings in a wall of said chamber;

a diaphragm disposed in said chamber and dividing said chamber into an operating chamber and a valve chamber;

a removable elastic seating ring disposed against said wall in said valve chamber, said seating ring having a first passage extending therethrough and communicating with said fluid inlet passage and second passage means communicating with said valve chamber on opposite sides of said seating ring, said seating ring having a valve seat disposed thereon and surrounding said first passage on a first surface of said seating ring facing said diaphragm;

valve operating means for selectively moving said diaphragm into contact with said valve seat to block flow of a fluid from said fluid inlet passage to said valve chamber; and

,

a diaphragm holder for pressing against a peripheral region of a first surface of said diaphragm, said seating ring having a peripheral projection on its first surface against which said diaphragm is pressed to thereby clamp said diaphragm, said seating ring having first and second annular projections on a second surface of said seating ring facing said wall, said first annular projection surrounding said first passage and said second annular projection extending along the periphery of said second surface, said first annular projection extending outwardly from the second surface of the seating ring further than said second annular projection whereby said first annular projection forms a fluid seal with said wall when said diaphragm is pressed against the peripheral projection on the first surface of the seating ring.

2. A diaphragm valve as claimed in claim 1 wherein said seating ring is provided with a groove and said valve seat comprises a synthetic resin material disposed in said groove.

3. A diaphragm valve as claimed in claim 1 wherein said valve seat and said seating ring comprise a monolithic body.

4. A diaphragm valve as claimed in claim 1 wherein said seating ring is provided with a groove and said second annular projection comprises a synthetic material disposed in said groove.

5. A diaphragm valve as claimed in claim 1 wherein said seating ring and said second annular projection comprise a monolithic body.

6. A diaphragm valve as claimed in claim 1 wherein said seating ring, second annular projection and valve seat comprise a monolithic body.

7. A diaphragm valve as claimed in claim 1 wherein said seating ring comprises an elastic metallic body.

8. A diaphragm valve comprising:

a valve body having a chamber, a fluid inlet passage and a fluid outlet passage communicating with said chamber through openings in a wall of said chamber;

a diaphragm disposed in said chamber and dividing said chamber into an operating chamber and a valve chamber;

a removable elastic seating ring disposed against said wall in said valve chamber, said seating ring having a first passage extending therethrough and communicating with said fluid inlet passage and second passage means communicating with said valve chamber on opposite sides of said seating ring, said seating ring having a valve seat disposed thereon and surrounding said first passage on a first surface of said seating ring facing said diaphragm;

valve operating means for selectively moving said diaphragm into contact with said valve seat to block flow of a fluid from said fluid inlet passage to said valve chamber; and

,

a diaphragm holder for pressing against a peripheral region of a first surface of said diaphragm said seating ring having a peripheral projection on its first surface against which said diaphragm is pressed to thereby clamp said diaphragm,

said seating ring having first and second annular projections on a second surface of said seating ring facing said wall, said first annular projection surrounding said first passage and said second annular protection extending along the periphery of said second surface, said first annular projection extending outwardly from the second surface of the seating ring further than said second annular projection whereby said first annular projection forms a fluid seal with said wall when said diaphragm is pressed against the peripheral projection on the first surface of the seating ring said first annular projection projecting about 0.5 mm further than the second annular projection from the second surface of the seating ring.