The pressure spring coded K 74135 provides the necessary preload within the fuel transfer pump of the Sulzer ZV40/48 engine, maintaining constant contact between moving parts and compensating for wear over time. Its calibrated tension ensures that valves and seals engage correctly, preserving consistent fuel pressure and preventing pulsation. Made from fatigue-resistant alloy, the spring withstands the high-cycle demands and thermal variations typical of continuous pump operation. Proper spring performance is critical to fuel system efficiency and engine responsiveness.