The nut marked with code number K 73125 is engineered to secure shaft K 73123 within the raw water pump assembly of the Sulzer ZV40/48 engine. Its function is fundamental—locking key rotating components in place to prevent mechanical failure under dynamic load. Designed to resist loosening due to vibration and high-speed operation, this precision nut plays a pivotal role in the long-term reliability and safety of the pump mechanism. Proper torque application and regular checks are essential to maintaining its securing function.