Valves have two cylindrical springs - external and internal, sandwiched between the plate (up) and two support washers (at the bottom). The plate of springs is held on the valve stem by two crackers, which, when folded, have the shape of a truncated cone.
To increase the wear resistance of the rod, both valves are nitrided, and the ends of the rods, on which the levers rest, are hardened by high-frequency currents.