... Type:Seamless steel pipe/welded pipe/galvanized steel pipe/ square tube/spiral steel pipe/ERW steel pipe ,etc.A)Seamless steel ... boiler, ship, liquid service, petroleum cracking, chemical ferticizer equipment, drawing-oil-equipment and structure purposes.6.Surface: oiled or black painted ... /2-26inch (diameter)2.Wall thickness: 1.8mm-30mm3.Standard: API5L,API5CT,ASTM A106,ASTM A53,SY5037-2000,GB/T9711.1 ...