Solid riders or wear rings, AAVOLYN Type 450, are required where the ring groove on the piston travels out into the valve area or cylinder counterbore. The solid, stretch on ring is designed to stretch over the piston diameter and then fit tightly on the ring groove. Proper strain and memory considerations are important to ensure that the solid ring remains tightly on the piston during operating temperatures and pressures. Pressure relief designs are available in high temperature applications where riders have a tendency to come loose on the piston in service. This allows gas, trapped under the ring, to bleed away, thus eliminating rapid wear of the ring and possible breakage.
