초록 ▼

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

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.

대표청구항 ▼

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a container for liquid which evaporates to build-up pressure in the container to a positive value and which can be withdrawn from the container to reduce the pressure therein to a negative value comprising a housing

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a container for liquid which evaporates to build-up pressure in the container to a positive value and which can be withdrawn from the container to reduce the pressure therein to a negative value comprising a housing having an outer flange thereon and a wall portion thereon formed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.