Pressure vacuum relief valve assembly

• US 3,937,358 A
• Filed: 09/09/1974
• Issued: 02/10/1976
• Est. Priority Date: 06/25/1973
• Status: Expired due to Term

• Current Assignee: General Motors Corporation (Motors Liquidation Co. GUC Trust)
• Original Assignee: General Motors Corporation (Motors Liquidation Co. GUC Trust)
• Inventors: Williams, Donald L., Smith, Claude A.
• Primary Examiner(s): Price, William
• Assistant Examiner(s): Shoap, Allan N.
• Application Number:
  US05/504,138
• Time in Patent Office: 519 Days
• Field of Search: 220/203, 220/303, 220/288, 220/210, 220/202, 137/493, 137/493.6, 137/493.7
• US Class Current: 220/203.18
• CPC Class Codes: B60K 15/0406 Filler caps for fuel tanks
• CPC Class Codes: B65D 51/1644 the element being a valve B65D51/1661 takes precedence

Abstract

A pressure vacuum relief assembly for a container includes a housing with a first port in communication with the container and a second port in communication with atmosphere; the housing encloses improved vacuum and pressure relief valve means including first and second diaphragm members each having central openings therein engageable with conical surfaces on vacuum relief and pressure relief seal members; said first and second diaphragms form a control chamber in communication with the first port which is selectively pressurized to cause selective snap movement of each of the diaphragms to control flow across the seal members between atmosphere and the container.

Claims

1. A pressure-vacuum relief valve assembly for a semi-closed liquid vapor system having a container for liquid which evaporates to build-up pressure in the container to a positive value and which can be withdrawn from the container to reduce the pressure therein to a negative value comprising a housing having an outer flange thereon and a wall portion thereon formed transversely of said outer flange, said housing further including an internal flange located radially inwardly of the outer flange in spaced relationship therewith, a first apertured spring diaphragm having an outer periphery thereon supported by said internal flange, said first diaphragm and wall portion defining a vacuum relief chamber, passage means in said housing communicating said vacuum relief chamber with atmosphere, a second apertured spring diaphragm having a peripheral portion thereon supported in sealing relationship with the outer periphery of said first diaphragm and being spaced with respect to said first diaphragm to form a pressurizable control chamber therebetween, passage means for directly communicating the interior of said pressurizable control chamber with the interior of a container, a vacuum relief seal member on said wall portion interposed within said first apertured diaphragm to control flow from said vacuum relief chamber through the passage means between said pressurizable control chamber and said container for vacuum relief at a predetermined negative pressure range, a pressure relief seal member interposed within said second apertured diaphragm between said control chamber and atmosphere, said second diaphragm operative in response to a predetermined build-up of pressure within said control chamber to open communication between the interior of said housing and atmosphere thereby to relieve a predetermined positive pressure range within the control chamber.

2. A pressure-vacuum relief valve assembly for a semi-closed liquid vapor system having a container for liquid which evaporates to build-up pressure in the container to a positive value and which can be withdrawn from the container to reduce the pressure therein to a negative value comprising a housing having a peripheral wall defining a housing bore, a partition wall in said housing formed transversely of said peripheral wall at one end of said bore, a cover on said housing overlying the opposite end of said bore, a plurality of ports formed through said peripheral wall to define vacuum relief passages in communication with atmosphere, each of said ports being located on a chord line through the circumference of the peripheral wall, an internal baffle ridge on said housing within said peripheral wall intersecting each of said ports and forming a curvilinear surface for separating particulates from vacuum relief air flow into said housing bore, vacuum relief valve means within said housing bore between said partition wall and said cover including an opening in said partition wall for communicating said vacuum relief ports with a container upon a predetermined vacuum condition occurring within the container to relieve the container against vacuum collapse, pressure relief port means including a space between said cover and said housing bore, and pressure relief valve means interposed between said partition wall opening and said cover responsive to a predetermined pressure build-up within said container to cause relief of pressure build-up therein through said pressure relief port means to prevent a build-up of excessive pressure within the container.

3. A pressure-vacuum relief valve assembly comprising a housing member having relief passage means therein adapted to be in communication with pressure within a container, a first spring diaphragm having a peripheral portion thereon sealingly connected to said housing and forming therewith a vacuum relief chamber, port means in said housing communicating said vacuum relief chamber with atmosphere, a second spring diaphragm having an outer periphery, means sealingly connecting the outer periphery of said second diaphragm to the periphery of said first diaphragm to form a variable pressure control chamber therebetween, said relief passage means being in direct communication with said pressurizable chamber for varying the pressure therein in accordance with pressure conditions within the container, a vacuum valve seal element in said relief passage means including a conical surface thereon, a central opening in said first spring diaphragm including an annular edge portion thereon engageable with said conical surface to form a normally closed seal therebetween, said first spring diaphragm being movable upon a predetermined minimum pressure within said pressurizable control chamber to cause said first diaphragm to shift so as to open communication between said vacuum relief chamber and said pressurizable control chamber thereby to communicate atmosphere with the container through said relief passage means, a pressure relief valve seal element having a conical skirt thereon located axially of said vacuum relief valve element in spaced relationship thereto, said second diaphragm including a central opening therein in communication with atmosphere having a raised annular edge therearound, said annular edge of said second spring diaphragm being normally engaged with said pressure seal conical skirt to seal thereagainst when normal pressure conditions exist within the container, said second spring diaphragm responding to a predetermined increase in pressure within the container to move so as to locate the second diaphragm edge in spaced relationship to said pressure seal element skirt thereby to exhaust pressure from the container through said relief passage means, said pressurizable control chamber and said second diaphragm opening to atmosphere.

4. A pressure-vacuum relief valve assembly for a semi-closed liquid vapor system having a container for liquid which evaporates to build-up pressure in the container to a positive value and which can be withdrawn from the container to reduce the pressure therein to a negative value comprising a housing having an outer flange thereon and a wall portion thereon formed transversely of said outer flange, said housing further including an internal flange located radially inwardly of the outer flange in spaced relationship therewith, a first spring diaphragm having an outer periphery thereon supported by said internal flange, said first diaphragm having a central opening therethrough, an annular gasket member supportingly received on the outer periphery of said first diaphragm, a second diaphragm member having a periphery thereon in sealing engagement with said gasket, a retainer member having the outer periphery thereof in engagement with the outer periphery of said second diaphragm and including a portion thereof in interlocking engagement with said outer flange to secure said first and second diaphragms in sealing engagement with said gasket, said transverse wall portion having a central opening therethrough in communication with a container, a pressure seal member having an apex portion thereon secured centrally of said retainer and including a downwardly depending conical skirt thereon defining a first valve seat, said second diaphragm including an annular edge formed centrally thereof engageable with said conical skirt to form a pressure relief valve, a vent member directed through the central opening in said transverse wall portion, a vacuum seal member having an apex portion thereon secured to said vent member and including a downwardly depending conical skirt thereon defining a second valve seat, an annular edge formed centrally of said first diaphragm engageable with said vacuum seal member skirt to form a vacuum relief valve, said transverse wall portion and said first diaphragm cooperating to form a vacuum relief space, said first and second diaphragms cooperating to form a control pressure chamber for operating said second diaphragm between opened and closed positions, means forming a pressure relief passage from said housing in communication with atmosphere, said housing including a plurality of passages therein located on chord lines through the circumference of said outer flange to communicate said vacuum relief space with atmosphere, said first and second diaphragms responding to a predetermined pressure increase within the container to cause said first diaphragm to seal against said vacuum seal member and to cause said second diaphragm to move away from said pressure seal member to communicate the vent member with atmosphere during a pressure relief mode of operation, said first and second diaphragms responding to a predetermined reduction in pressure within the container to reduce the pressure in the control pressure chamber between said first and second diaphragms so as to cause said second diaphragm to be held by atmospheric pressure against said pressure seal member and to cause said first diaphragm to move from said vacuum seal member to communicate atmosphere with the space between said diaphragms thence through said vent member into the container.

5. A valve closure for sealing between a first source of pressure and a second source of pressure comprising a valve housing having a bore therethrough, a spring diaphragm having an outer periphery fixedly secured to said housing, a dished center portion on said diaphragm separating said housing into first and second pressure chambers, wall means on said diaphragm including a turned edge forming a central aperture therein to define a flow passage between said first and second chambers, a seal element having a flexible skirt of conical configuration, means for supporting said skirt coaxially of said central aperture for engagement with said wall means to seal said central aperture against flow therethrough, said diaphragm being responsive to a predetermined pressure differential between said first and second chambers to cause said wall means to snap axially of said skirt to produce an annular open flow area between said aperture and said skirt, said diaphragm being responsive to a reversal of pressure differential between said first and second chambers to close said turned edge against said skirt in an action wherein said turned edge wipes the surface of said skirt.