Fuel check valves and overflow valves: 15 listings from PAI Industries, Detroit Diesel and Interstate-McBee. A check valve keeps fuel from draining back so the system holds prime; a leaking one often shows up as long cranking after the truck sits, or air in the fuel lines.
Detroit Diesel Series 60 (12.7L and 14L) has the most coverage: Detroit Diesel 23516918, 23516919 and 23537213, PAI 645050, 645051 and 645052, and the 23535129 valve (PAI 645053 and Interstate-McBee A-23535129). For Cummins there are N14 valves PAI 042211 (replaces 3348332) and PAI 180233, PAI 042210 (OEM 3028325) and Cummins 217196 (PAI 180120). Also listed: the PAI 840071 fuel overflow valve for Mack MP7/MP8 and Volvo D11/D13, and PAI 380170 for Caterpillar 3406E (replaces 2812725).
Match the OEM number on the valve body. More fuel parts are in fuel system.