Why are small-diameter valves meeting American standards such as globe valves, stop valves, and check valves made of forged steel, while ball valves are made of cast steel?

The choice between forged steel and cast steel for small-diameter valves meeting American standards is usually determined by the valve’s pressure rating, size, manufacturing cost, and intended use. Forged steel, with its good material uniformity, high strength, excellent heat resistance, and superior compressive properties, is suitable for manufacturing small-diameter, high-pressure globe valves, gate valves, and check valves. These valve types are often used in high-pressure systems and require good sealing properties and strength to withstand pressure shocks. As for ball valves, they generally require larger fluid passages than globe valves and gate valves; therefore, they are often made of cast steel. The casting process is more economical and convenient for producing parts of larger size or complex shapes compared to forging. However, in applications with high performance requirements, small-bore ball valves may also be made of forged steel to meet specific pressure and durability demands. Different pressure ratings (such as CL800 vs CL150) refer to the maximum pressures that the valve can withstand. Although the material is the same, such as forged steel, the design and structure may vary depending on the pressure rating. This explains why even valves of the same type and size can still have differences in pressure rating and other parameters. Data inconsistency may be due to variations in how different manufacturers interpret product specifications, or to specific requirements in the market for various application environments. Therefore, when selecting the appropriate valve, it is important to consider the specific application scenario and technical requirements. .