stainless welded steel pipe Standard : ASTM API ASTMA53 GRA GRB Grade : API5L X42 X46 X52 X56 X70 , B GRA GRB Tangshan Fengrun Kaiwei Steel Co ... :Mainly used for conveying water, gas, air, oil and heating hot water or low pressure steam and other fluids, and other ... :Mainly used for conveying water, gas, air, oil and heating hot water or low pressure steam and other fluids, and other ...