ALUMINUM PISTON WITH RING RETAINER
The rings are used to seal combustion gases during the piston's operation in the liner and to control the oil film around the liner. The channel in which this ring is attached to the piston is specially manufactured in diesel engine pistons and is called the ring retainer. Since the piston head forms the lower surface of the combustion chamber, it must be resistant to high temperature and pressure. For this reason, it is covered with adhesive material called ring retainer (alfin). It adheres to the piston under the influence of temperature during casting. With this method, the strength of the piston is increased and its life is extended.