Metal elastic force ring inside piston rings can add initial elastic force of the non-metallicpiston ring to get expectative seal effect.
在活塞环的内侧设置金属的弹力环增加非金属活塞环的预弹力，可到达预期的密封效果。
2
Metallic detergent and ashless dispersant additive system provides superior control of ring belt and piston skirt deposits, even under the most severe operating conditions.