The O-ring K 73137 is a precision elastomer sealing component used in bearing housing K 73111 within the Sulzer ZV40/48 raw water pump assembly. Its function is to provide a static seal between mating surfaces, preventing leakage of fluids and ingress of contaminants. Designed to maintain elasticity and sealing integrity under temperature changes, pressure variations, and vibration, this O-ring ensures consistent sealing performance over long service intervals. Its accurate fit and durable material properties support system integrity, protect internal components, and contribute to the efficient and reliable operation of the pump and overall engine cooling system.