ASTM A182 – Forged or Rolled Alloy and Stainless Steel Pipe Flanges, Forged Fittings, and Valves and Parts for High-Temperature Service Grade: F11 Class1, Class2 and Class3 Chemical Requirements   max,% Elements F11 Class1 F11 Class2 F11 Class3 Carbon 0.05-0.15 0.10-0.20 0.10-0.20 Manganese 0.30-0.60 0.30-0.80 0.30-0.80 Phosphorus 0.030 0.040 0.040 Sulfur 0.030 0.040 0.040 Silicon 0.5-1.0 0.5-1.0 0.5-1.0…