Both WCC and WCB valves are made of ASTM A216 standard cast carbon steel. The core differences between the two are as follows:
1. Material composition difference
Carbon content (C)
WCB: The carbon content is limited to 0.30% (maximum allowable value);
WCC: The carbon content range is wider (0.25%~0.55%), and the welding and casting performance can be optimized by adjusting the carbon content.
Manganese content (Mn)
WCB: Manganese content ≤1.00%;
WCC: The manganese content is increased to 1.20%, which enhances the toughness of the material.
2. Comparison of mechanical properties
Yield strength : WCC yield strength ≥275MPa, higher than WCB's ≥250MPa;
Tensile strength : The two are the same (485–655MPa);
Elongation : Both require ≥24%, but WCC has a higher manganese content and better actual impact resistance.
3. Application scenario selection
Versatility: WCB is the most commonly used carbon steel valve material, covering -30°C~425°C conventional working conditions (water, steam, oil and gas);
High performance requirements: WCC is more suitable for: Pipeline systems with frequent vibration or large pressure fluctuations due to its strength and toughness advantages;
Low temperature environment (above -46°C), but the impact test data still needs to be verified;
Critical pipe sections that require a higher safety factor.
Note: Both are not suitable for high temperatures >425°C or highly corrosive media.
Such working conditions need to be upgraded to WC6 (chrome-molybdenum steel) or CF8 stainless steel.
4. Selection recommendations
Economic priority: Choose WCB for conventional working conditions (lower cost and wider supply);
Strength priority: Choose WCC when there is a risk of water hammer, frequent start-stop or low temperature;
Alternative materials: In forged valves, both correspond to forged steel grade A105. Both types of valves are manufactured to the same standards (such as API 600/ISO 10434), and the only difference is the casting material grade.
