Raptors, the authorized dealer of Cummins (China), established in 2015 by Mr. Jordan Wang who worked in Cummins (China) for 8 years, Jordan had been responsible for mine market for 4 years during working in Cummins china, so we have big advantages for almost all genuine Cummins generators, engine assembly and spare parts, especially for NTA855, KTA19, KTA38, KTA50, QSK60, QSX15 etc...The composition of the fuel pumpThe fuel pump is composed of an electric motor, a pressure limiter, and a check valve. The electric motor actually works in the fuel in the oil pump casing. Don't worry, because there is nothing in the casing that can be ignited. The fuel can lubricate and cool the fuel motor. The oil outlet A check valve is installed at the pump, and a pressure limiter is located on the pressure side of the oil pump housing with a passage to the oil inletHow the fuel pump worksWhen the rotor disc rotates, the roller is pressed outward by centrifugal force, like a rotating oil seal, the rotor rotates, the pump works, sucks fuel from the oil inlet, and presses the fuel from the oil outlet into the fuel system, when the oil pump is turned off , the check valve at the oil outlet is closed to prevent the fuel from flowing back to the fuel tank through the fuel pump, and the fuel line pressure maintained by the check valve is called "residual pressure