The joint ring bearing code number K 81259 is a sealing element designed for use with the screw plug K 81258 in the Sulzer ZV40/48 engine. Its primary function is to provide a leak-proof seal between the plug and the housing, ensuring that fluids such as oil or coolant remain contained under pressure. Manufactured from resilient and heat-resistant material, the joint ring is essential for maintaining the engine's operational integrity and avoiding performance issues caused by leaks or pressure loss.