Boiler pipes are seamless steel pipes of various thicknesses used in trade for general purposes EN 10216-1:2005 (EX UNI 7287/86) or for the construction of simple pipelines, such as those of the boiler, through which steam generated by boiling heating water flows.
Boiler pipes are therefore suitable pipes for supporting the passage of gas at high temperatures, and they are typically made by cold drawing, which results in a pipe with high mechanical compactness.
Of course, boiler pipes can be made in a variety of thicknesses and diameters, as well as steel with various properties depending on the intended use.
for more info visit -   ASTM A210 Grade A1 Boiler Pipes