... . Tubes used for low and medium pressure boiler working at a temperature below450°C ,Tubes , economizer, superheater and reheater, petrochemical line ... ,20MnG,25MnG,15CrMoG,12Cr2MoG,12Cr1MoVG,12Cr2MoWVTiB,10Cr9Mo1VNbetc.ASTM: Grade A,C,D, Grade A-1,C,BS: 320 CFS, 440,243,620-460 ...