Cast Iron vs. Cast Steel Valves: What's the Difference?

When specifying valves for industrial and municipal applications, engineers frequently choose between Cast Iron and Cast Steel. While they might sound similar, their properties and ideal use cases differ significantly.

Understanding Cast Iron valves

Cast Iron valves (often made from ASTM A126 Class B) are celebrated for their excellent machinability and vibration dampening characteristics. They are the go-to choice for low to medium pressure systems.

• Applications: Water supply, Sewage, HVAC systems.
• Pressure: Typically PN10 or PN16.
• Advantages: Cost-effective, very rigid, resistant to deformation.

Understanding Cast Steel Valves

Cast Steel valves (such as ASTM A216 WCB) are designed for high temperature and high-pressure environments. They possess higher tensile strength and better impact resistance compared to Cast Iron valves.

• Applications: Oil & Gas, Petrochemical, Power Plants, Steam lines.
• Pressure: Class 150, 300, 600 and above.
• Advantages: Can handle extreme pressures and thermal shock, welded easily.

Which One Should You Choose?

If your project involves water distribution networks, cooling towers, or standard commercial HVAC, Cast Iron valves provide the best balance of performance and economy. For critical oil refineries or high-pressure steam, Cast Steel is necessary.