Common replacement parts and their Presto model numbers: Sealing Ring (9936), Over Pressure Plug (9915), Pressure Regulator - 15 PSI (9978). A 3-piece regulator set (50332) is for pressures lower than 15 PSI.
Other serviceable parts include the Interlock Assembly (85610), Interlock Assembly Gasket (85660), and handles (Cover Handle 85637, Body Handle 85638).