A flange for a pressure vessel includes a rim, a sealing seat, and an undercut fillet. The rim has an annular surface for abutting an annular end of a cylindrical wall of the pressure vessel. The sealing seat has a cylindrical surface for abutting an inner surface of the cylindrical wall of the pressure vessel nearby the annular end. The undercut fillet is disposed between the rim and the sealing seat. A concave surface of the undercut fillet extends the annular surface of the rim radially inward and then curves back outward to intersect the cylindrical surface of the sealing seat. The undercut fillet of the flange helps distribute stress produced from a pressure differential between the inside and outside of the pressure vessel.

A pressure vessel comprising a pipe closed at each end with a novel plug/compression cap, the plug at one end of the pipe having a port for connection to a pressure regulating device.

A cylinder filling system is configured to automatically fill fluid cylinders with fluid at varying fluid pressures. The cylinder filling system may include a plurality of pressure control manifolds operatively connected together and disposed in a fluid circuit between a fluid storage container and a fluid outlet. A control unit may be in communication with the plurality of pressure control manifolds. The control unit is configured to operate the plurality of pressure control manifolds to deliver fluid at a rated fluid pressure of a fluid cylinder that connects to the fluid outlet.

Gas-filling system including a base manifold having a flow-control component and a manifold body that is operably coupled to the flow-control component. The manifold body includes a fill port and first and second supply ports that open to an exterior of the base manifold. The first and second supply ports are in fluid communication with a common passage within the manifold body such that the gas flowing through the first supply port or through the second supply port flows through the common passage to the fill port. The fill port is configured to be in fluid communication with a container. The gas-filling system also includes an accessory module removably coupled to the manifold body. The accessory module is connected to the first supply port and has an inlet port.

A depth selector or current depth provider for use by a variable speed air system. As a depth selector it is preferably in the form of a rotary switch on the user interface for the air system. The rotary switch can have 3 positions for maximum depth selections, such as, without limitation 15, 25, and 65 feet. Other depth values and number of depth selections provided can be used and all are considered within the scope of the disclosure. A microcontroller of the system reads the voltage from the voltage divider created by the rotary switch selection to determine which position the rotary switch is in. The microcontroller uses this information to set the upper and lower pressure limits for the dive.

A depth selector or current depth provider for use by a variable speed air system. As a depth selector it is preferably in the form of a rotary switch on the user interface for the air system. The rotary switch can have 3 positions for maximum depth selections, such as, without limitation 15, 25, and 65 feet. Other depth values and number of depth selections provided can be used and all are considered within the scope of the disclosure. A microcontroller of the system reads the voltage from the voltage divider created by the rotary switch selection to determine which position the rotary switch is in. The microcontroller uses this information to set the upper and lower pressure limits for the dive.

A pressure vessel includes curved sidewalls configured as a frame having a polygonal outline, a planar top side and a planar bottom side attached to the curved sidewalls forming a sealed pressure chamber therebetween. Each planar side includes a contoured surface having shaped pressure resistant features formed thereon. A preferred method for forming the pressure resistant features includes hydraulic pressurization to induce plastic strain. The pressure vessel also includes an array of internal support posts within the sealed pressure chamber attached to the planar sides in a geometrical pattern, such as a hexagonal array. The support posts can be solid metal cylinders, hollow tubes or tubes through which reinforcing materials, such as carbon fiber, glass fiber, or fiber/epoxy tape have been passed. A composite pressure vessel includes tubular internal support posts reinforced with reinforcing materials, as well as contoured surfaces and curved sidewalls reinforced with these same reinforcing materials.

A pressure vessel includes curved sidewalls configured as a frame having a polygonal outline, a planar top side and a planar bottom side attached to the curved sidewalls forming a sealed pressure chamber therebetween. Each planar side includes a contoured surface having shaped pressure resistant features formed thereon. A preferred method for forming the pressure resistant features includes hydraulic pressurization to induce plastic strain. The pressure vessel also includes an array of internal support posts within the sealed pressure chamber attached to the planar sides in a geometrical pattern, such as a hexagonal array. The support posts can be solid metal cylinders, hollow tubes or tubes through which reinforcing materials, such as carbon fiber, glass fiber, or fiber/epoxy tape have been passed. A composite pressure vessel includes tubular internal support posts reinforced with reinforcing materials, as well as contoured surfaces and curved sidewalls reinforced with these same reinforcing materials.

A depth selector or current depth provider for use by a variable speed air system. As a depth selector it is preferably in the form of a rotary switch on the user interface for the air system. The rotary switch can have 3 positions for maximum depth selections, such as, without limitation 15, 25, and 65 feet. Other depth values and number of depth selections provided can be used and all are considered within the scope of the disclosure. A microcontroller of the system reads the voltage from the voltage divider created by the rotary switch selection to determine which position the rotary switch is in. The microcontroller uses this information to set the upper and lower pressure limits for the dive.

A pressure vessel formed by either by: a) mating a first end or closure to a second end or closure or b) mating a first end to an intermediate body member and mating the intermediate body member to a second end; the first end comprising a hollowed thin walled dome (14) having an exterior surface (15a) and an interior surface (15b) and the dome terminating in an edge surface (14a), the dome (14) having an axis Y extending through its geometric center of the exterior surface, the dome supporting at least one thin hollow walled projection (16, 18, 20) having an exterior (19a) and interior surface (19b), the at least one projection extending outwardly from the dome outer surface (15a), and terminating in a top surface (16a, 23).