63. What is the purpose of the delivery check valve used in a diesel fuel injection jerk pump?

The delivery check valve in a diesel fuel injection jerk pump facilitates a rapid fuel cutoff, preventing fuel dribble from the nozzle. This valve opens during pressurization and quickly closes to create a sharp pressure drop, ensuring clean combustion. Fuel metering is controlled by the plunger helix and spill port, and the valve prevents backflow and maintains residual pressure, not reducing pressure or allowing oil backflow.