Under high temperature (≥450℃) or strong wash working conditions, sphere choose Ni60 (hardness about HRC58-62), valve seat choose Ni55 (HRC52-56) can form hard-tough pair. Suggest
Stellite in high-temperature ball valves usually is better: its melting point is about 1285–1410°C, corrosion resistance is close to stainless steel, and impact resistance and
WC hardness HRC65–75, wear resistance best, suitable for containing >25% particle medium, lifespan improves 3 times but cost high about 20%; Stellite hardness HRC40–50, temperature
In API 6D ball valves: WC coating hardness reaches HRC65–75, suitable for containing 30–40% solid particles medium, wear resistance lifespan improves 3–5 times; but temperature
Under harsh working conditions, tungsten carbide valve seat usually more wear-resistant, hardness can reach HRA 88~92, lifespan often compared to Stellite increased by 2~5 times;
Under strict inspection requirements, forged valve body is better: density ≥ 98%, tensile strength increased by 20%~30%, airtight leakage rate ≤ 1×10⁻⁶. Cast parts easily
When valve body and valve cover need 100% RT inspection, casting pass rate is about 85%-90%, rework cost is high; Forging internal is dense, RT
RT inspection is radiographic flaw detection, used to discover cast steel valve internal porosity, shrinkage and other defects. According to standard (such as ASTM E446),
In export projects, forged valve body strength is high (tensile strength ≥450MPa), suitable for high pressure (>PN100) European and American markets; Cast valve body cost
Cast valve body cost is lower by about 20%-30%, suitable for complex structures, but easy to have blowholes, strength slightly lower; Forged valve body density
