T #delivery valve in fuel injection pump 131110 0320 video 131110-0320 50S5#

Main Function

1. At the end of the plunger’s upward fuel delivery stroke, the delivery valve prevents a reverse flow of fuel from the injection line.

2. Figure 19-24 illustrates the sucking action that occurs at the delivery valve piston portion which controls the residual pressure in the injection line so as to effectively improve the injected spray pattern of the fuel without fuel dribble and possible secondary injection. The sucking action that does occur at the delivery valve therefore effectively reduces the fuel pressure in the injection tube at the end of injection.

The delivery valve is mounted on the distributive head of injection pump. The valve spring and delivery valve are mounted in the delivery valve holder. The surface of the delivery valve seat is made with high precision. Delivery valves are responsible to separate the high-pressure circuit between the pressure line and the pump plunger. Right after the fuel injection, the nozzle section is adjusted to a specified pressure. That's how the exactly timed closure of the nozzle is secured and undesired dripping is