Abstract: A unitary valve housing has an upper and lower portion. The upper portion has an inner chamber for accommodating two spaced apart balls and a cylindrical side skirt with oppositely positioned openings. The lower portion is cylindrical in shape and has a top shelf with adjacent circular openings for seating the two balls and openings communicating with a bottom of the lower portion. The two openings on the upper portion side skirt are aligned with oppositely positioned openings in a side of the lower housing. A secondary shelf is located in the lower housing below each of the two circular openings contiguous with the side openings. A lower end of the lower housing portion is attached to a conduit.

Abstract: A unitary valve housing has an upper and lower portion. The upper portion has an inner chamber for accommodating two spaced apart balls and a cylindrical side skirt with oppositely positioned openings. The lower portion is cylindrical in shape and has a top shelf with adjacent circular openings for seating the two balls and openings communicating with a bottom of the lower portion. The two openings on the upper portion side skirt are aligned with oppositely positioned openings in a side of the lower housing. A secondary shelf is located in the lower housing below each of the two circular openings contiguous with the side openings. A lower end of the lower housing portion is attached to a conduit.

Abstract: A combined vacuum relief and pressure containing valve assembly for relieving vacuum developing within an associated vessel and for containing elevated pressures developing within the vessel. The valve assembly has a housing having two communicating passageways demarcated by a valve seat. The first passageway communicates to the open atmosphere and also with the valve from below the valve seat. The valve is a ball constrained to move only vertically above its seat. The second passageway communicates with the valve from above the valve seat. The second passageway extends below the valve so that when the valve assembly is connected to the associated vessel, pressures prevailing within the vessel act on the valve from above. Therefore, vacuum prevailing within the vessel, acting in concert with relatively higher ambient temperatures, will draw the valve into the open position. At zero pressure differential, gravity urges the valve into the closed position and maintains a seal.

Abstract: A combined vacuum relief and pressure containing valve assembly for relieving vacuum developing within an associated vessel and for containing elevated pressures developing within the vessel. The valve assembly has a housing having two communicating passageways demarcated by a valve seat. The first passageway communicates to the open atmosphere and also with the valve from below the valve seat. The valve is a ball constrained to move only vertically above its seat. The second passageway communicates with the valve from above the valve seat. The second passageway extends below the valve so that when the valve assembly is connected to the associated vessel, pressures prevailing within the vessel act on the valve from above. Therefore, vacuum prevailing within the vessel, acting in concert with relatively higher ambient temperatures, will draw the valve into the open position. At zero pressure differential, gravity urges the valve into the closed position and maintains a seal.

Abstract: A valve head includes an annular valving plate made of a resilient material and a valve guide including projecting legs with elongated slots designed to couple with fins located on the valve body to provide valve guidance between open and closed positions. The valving plate and valve guide are assembled together by heating them to a sufficient temperature to permit a thin layer of the guide to melt and fuse with the valving plate.