The Adapter (AM, AF) check valve is a one-piece body valve machined from bar stock. This is designed to be installed where threaded straight adapter pipe fittings are desired. The adapter check valve is available in AM (MNPT x FNPT) or in AF (FNPT x MNPT) configurations. This valve can also be used in low-pressure or vacuum relief applications by using the desired spring settings. NPT threads are per ASME B1.20.1.