The size of stainless steel heat exchange tubes is the outer diameter multiplied by the wall thickness. The commonly used sizes include seamless steel pipes with diameters of 19mmx2mm, 25mm x2.5mm, and 38mmx2.5mm, as well as stainless steel pipes with diameters of 25mm x2mm and 38mmx2.5mm.
Standard pipe lengths: 1.5, 2.0, 3.0, 4.5, 6.0, 9.0m, etc., among which the commonly used specifications are 25mm x 2.5.