A breather valve for a tank having coaxial flat disc pressure and vacuum relief valves seated on opposite sides of a fitting threaded to a connection on the tank. The outer disc has an axial stem slidably guided by the fitting and the inner disc is slidable on the stem. The discs are commonly biased by a spring between the end of the stem and the inner disc.
A combined air vent and overpressure relief valve for a submersible pump includes a single tubular housing to be inserted in an opening in the upper end wall of a chamber on the outlet pressure side of the pump. The upper end of this housing has a vent hole therethrough, and inside the housing is an annular valve seat facing upwardly. A valve disk within the housing is proportioned to move lengthwise thereof toward and away from the valve seat but is normally biased into sealing engagement with the seat by a spring within the housing. This valve disk has a bleed hole therethrough, and a valve ball is caged in the lower part of the housing, below the valve seat for movement into and out of sealing engagement with the lower end of the bleed hole in the valve disk as the pressure within the chamber rises and falls. If that pressure exceeds the force of the spring holding the valve disk closed, the disk will be forced out of sealing engagement with its seat in the housing, thereby providing a flow path for liquid around the periphery of the disk to and through the vent hole in the upper end wall of the housing.
A two-way valve for introducing pressurized air into the air chamber of an air shock absorber, and for maintaining a preselected minimum pressure within the air chamber. The valve includes a valve body and a valve cover mounted thereon. The valve body has an orifice in communication with the air chamber, and the valve cover has a fluid port in communication with a source of pressurized air. The valve cover includes a downwardly extending exhaust seat which surrounds the fluid port. Disposed within a recessed chamber in the valve body are an armature, an elastomeric diaphragm mounted on and supported by the armature, and a spring arrangement operatively positioned between the armature and the floor of the recessed chamber. The diaphragm is adapted to engage the exhaust seat when the pressure outside the air chamber is greater than the pressure inside the air chamber to permit the free flow of pressurized air into the air chamber, is adapted to unseat from the exhaust seat when the pressure inside the air chamber is greater than the pressure outside the air chamber and exceeds a preselected minimum pressure, to permit the controlled flow of air out of the air chamber, and is adapted to engage the exhaust seat when the pressure inside the air chamber reaches the preselected minimum pressure.
