Master fuel pump

A master fuel pump, in a common-rail two-stroke such as the Sulzer RT-flex or the MAN ME, is a high-pressure supply pump driven off the engine that charges the common fuel rail to injection pressure, from which solenoid-controlled injection valves draw for each cylinder. It replaces the bank of individual cam-driven jerk pumps, one per cylinder, of the older RTA and MC engines, so the same rail pressure feeds every unit and injection timing and quantity become software functions. Several pump elements feed one rail for redundancy. The arrangement holds injection pressure steady at low load, which improves combustion and lowers smoke during slow steaming.