Relief restrictor function - GF07.03-P-5005-01H

Engine 605, 606 

Fig 1: Identifying Relief Restrictor, Pressure Valve, Pressure Valve Holder And Plate Valve

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

The plate valve (16/9) with relief restrictor (16/7) are raised during injection. Fuel can flow freely into the injector nozzle. The plate valve (16/9) serves to dampen the rocking motion that is produced in the column of fuel following delivery. This prevents the nozzle needle from lifting and allowing secondary injection, thereby reducing the amount of hydrocarbon (HC) in the exhaust.