The fuel pump connections, code P51435-14, serve as the critical interfaces between the fuel supply lines and the high-pressure injection pump in the MAN L21/31 engine. Designed for precision alignment and leak-proof operation under high pressures, these connections ensure stable fuel delivery and reliable pump function. Their integrity is vital for maintaining injection efficiency and preventing pressure loss or air ingress, directly impacting engine performance, emissions, and long-term durability in both marine propulsion and auxiliary power systems.