The PRV-E-1800-1S is a single-stage, external return pressure relief valve designed as a direct replacement for LB7 and 5.9 style fuel systems operating at 1800 bar. Featuring an M18x1.5 thread, this valve maintains precise fuel rail pressure and protects your high-pressure common rail system from overpressure conditions at stock to mildly modified pressure levels. A reliable and precise aftermarket solution for diesel owners looking to restore or maintain proper fuel system function on Duramax LB7 and Cummins 5.9 platforms.