Boilermaking

A boilermaker is a trained craftsman who produces steel fabrications from plates and tubes. The name originated from craftsmen who would fabricate boilers, but they may work on projects as diverse as bridges to blast furnaces to the construction of mining equipment. The trade of Boilermaker evolved from the industrial blacksmith and was known in the early 19th century as a "boilersmith". The involvement of boilermakers in the shipbuilding and engineering industries came about because of the changeover from wood to iron as a construction material. It was easier (and cheaper) to utilize the boilermaker's skills to construct the ship as they were already present in the shipyard constructing iron boilers for wooden steamships. This utilization of skills extended to virtually everything that was large and made of iron, or later, steel. In the UK this virtual monopoly over the key skill of the industrial revolution led to them being termed 'the labour aristocracy' by historians.

In the USA many boilermakers are employed in repairing, repiping, and re-tubing commercial steam and hot water boilers used for heating and domestic hot water in commercial buildings and multi-family dwellings. Sometimes these boilers are referred to as pressure vessels. Generally, a pressure vessel is a storage tank or vessel that has been designed to operate at pressures above 15 psi (1.03 bar; 103 kPa). The two main tasks of boilermakers involve using oxy-acetylene gas torch sets to cut or gouge steel plate and tubes, followed by gas tungsten arc welding (GTAW), shielded metal arc welding (SMAW), or gas metal arc welding (GMAW) to attach and mend the cut sections of tubes and steel plates.

Boiler repair in the United States is governed by the National Board of Boiler and Pressure Vessel Inspectors and the ASME under a classification called R Stamp Welding. In order to perform R Stamp welds and repairs, boilermakers are tested and certified in the quality of their weld joints through a rigorous testing procedure. R stamps are issued to companies that have existing ASME code stamps issued for construction and whose QC system covers repairs or follow the guidelines set up by ASME to obtain an R stamp. Welders identify their welds by stamping their identifying welder number adjacent to their completed weld with a set of steel stencils.

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