An interchangeable fitting system generally involving a fitting, the fitting including a male connector and a female connector, the male and female connectors each having a forward portion and an aft portion, the male connector having a primary sealing structure and a secondary sealing structure, the female connector having a primary sealing structure and a secondary sealing structure, and the male primary sealing structure being interfaceable with the female primary sealing structure, and the male secondary sealing structure being interfaceable with the female secondary sealing structure.