The valves have two cylindrical springs - an outer and an inner one, clamped between a plate (top) and two support washers (bottom). The spring plate is held on the valve stem by two crackers, which have the shape of a truncated cone when folded.
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 with high-frequency currents.