Pressure regulator and safety relief valve

In an oxygen pressure regulator for maintaining constant lower pressure of oxygen gas delivered from a relatively high pressure source of the type including a casing having an internal flexible diaphragm dividing said casing into two major chambers, one chamber being vented to the atmosphere and containing adjustable resilient means for exerting a predetermined constant pressure against the diaphragm, and the other chamber being a gas chamber divided into two subchambers, a first inlet sub-chamber for receiving said high pressure gas and a second outlet sub-chamber for accumulating and delivering said gas at a lower pressure to an outlet means provided with valve-controlled inlet means connectable between said first and second sub-chambers to regulate the pressure of said gas in said outlet sub-chamber, the improvement comprising:

• a pressure relief valve in communication with said outlet sub-chamber, comprising in combination;
• a generally cylindrical housing having an inlet port and an outlet port said outlet port closed by a cap threadably engaging said housing, said cap having a plurality of apertures defining a flow path from said housing to the atmosphere;
• a valve closure member in the form of a stepped cylinder having a T-shaped cross-section with a generally cylindrical bore through said valve closure, said bore closed by a single combustible elastomeric element and also being positioned to close said inlet port, said valve closure slidably disposed within said housing and extending outwardly of said cap through a suitable aperture therein said valve closure member exterior and said housing coacting to effect a first passage means to allow passage of fluid from said inlet port to said outlet port when pressure in said outlet sub-chamber exceeds a given value;
• a spring disposed around the longer of the cylindrical sections of said valve closure and extending between the base of said cylindrical section of said closure and said cap to urge said valve closure member toward said inlet port to prevent passage of gas until the gas pressure at the inlet exceeds a preset limit said cap movable to adjust the tension on such spring to adjust the pressure at which said valve will open;
• whereby if combustion occurs inside said regulator, said combustible element will be consumed regardless of the pressure on said valve closure member, thus venting said combustion from said regulator to prevent cataclysmic failure of said regulator.