Boiler tubes are seamless tubes (ASTM A179) which are made of carbon steel (or alloy) or traditionally wrought iron. Seamless pipes are widely used in steam boilers, for power generation, in fossil fuel plants, industrial processing plants, electric power plants, etc. Boiler tubes can either be medium-pressure boiler pipe or high-pressure boiler tube.

Due to corrosion and stress corrosion cracking, stainless steel, particularly of the austenitic forms, is not used in wetted sections of boiler tubes. Ferritic stainless steel is, however, frequently found in overheated areas that are not subject to boiling water, and electrically heated stainless steel shell Boiler tubes are allowed for steam processing for sterilizers and disinfectors under the European“Pressure Device Guideline.”

Copper or brass is also used in live steam versions since it is cheaper to produce in smaller boiler tubes. Traditionally, copper is most often used in fireboxes because of its better formability and higher thermal conductivity; however, in recent years, copper prices have rendered this an economical option and then use affordable alternatives (such as steel).

The only commodity used in boiler construction during most of the Victorian “era of steam” was the lowest quality wrought iron, with mounting by riveting. This iron was primarily sourced from specialist ironworks, such as those in the Celator Moor region (UK), known for the high nature of their rolled steel, which was ideal for use in essential applications such as increased-pressure boiler tubes. Technology innovation in the 20th century shifted towards steel usage of welded production, which is safer and more straightforward, which can be made quicker and with less labour. Wrought iron boiler tubes corrode even more gradually than their counterparts in conventional steel and are less prone to irregular pitting and stress corrosion. The longevity of older wrought-iron boiler tubes is far superior to that of welded steel boiler tubes.