Boilermakers typically do the following:

• Read blueprints to determine locations, positions, and dimensions of boiler parts
• Install small, premade boilers in buildings and manufacturing facilities
• Lay out prefabricated parts of large boilers before assembling them
• Assemble boiler tanks, often using robotic or automatic welders
• Test and inspect boiler systems for leaks or defects
• Clean vats with scrapers, wire brushes, and cleaning solvents
• Replace or repair broken valves, pipes, or joints, using hand and power tools, gas torches, and welding equipment

Boilers, tanks, and vats are used in many buildings, factories, and ships. Boilers heat water or other fluids under extreme pressure to generate electric power and to provide heat. Large tanks and vats are used to process and store chemicals, oil, beer, and hundreds of other products.

Boilers are made of steel, iron, copper, or stainless steel. Most manufacturers have automated the production of boilers for improved quality. However, boilermakers still assemble and maintain boilers manually. For example, they often use hand and power tools and flame-cutting torches to align, cut, and shape pieces for a boiler. Boilermakers also use plumb bobs, levels, wedges, and turnbuckles to align pieces.

During a boiler installation, boilermakers align boilerplates and boiler parts, using metalworking machinery and other tools to remove irregular edges so that the parts fit together properly. If the plate sections are very large, boilermakers signal crane operators to lift the plates into place. Boilermakers then join the plates and parts by bolting, welding, and riveting them together.

Boilermakers may help erect and repair air pollution abatement equipment, blast furnaces, water treatment plants, storage and process tanks, and smokestacks. Boilermakers also install refractory brick and other heat-resistant materials in fireboxes or pressure vessels. Some install and maintain the huge pipes used in dams to send water to and from hydroelectric power generation turbines.

During regular maintenance, boilermakers inspect systems and their components, including safety and check valves, water and pressure gauges, and boiler controls. They also clean boilers and boiler furnaces and repair and replace parts, as needed.