The seal ring, code 136973, is a vital sealing component used in the MAN L21/31 engine to prevent leakage and maintain controlled pressure conditions within mechanical and hydraulic systems. Installed at critical sealing interfaces, it forms a dependable barrier against the escape of oil, fuel, coolant, or air while protecting the engine from the ingress of contaminants. Designed to accommodate thermal expansion, vibration, and operational movement, the seal ring helps preserve system integrity even under demanding marine and industrial operating conditions. Manufactured from durable, wear-resistant, and chemically resistant materials, it contributes to improved engine efficiency, reduced maintenance requirements, and extended service life of essential engine assemblies.