The spring identified with code K 87091 is an essential load-bearing element within the pressure regulating valve of the ZV40/48 engine. Its purpose is to apply the necessary preload force that determines the valve’s opening pressure, allowing precise control of fluid or gas flow under varying operational conditions. Built from high-tensile alloy steel, the spring resists fatigue and deformation across thousands of cycles, ensuring consistent pressure regulation. Its resilience directly affects system efficiency, safety, and responsiveness in both marine and industrial applications.