A spool piece is a prefabricated piece of pipe that is created to match the needs of a particular project. In the piping industry, a spool piece is also known as a pipe spool.
The prefabrication of piping spools is necessary because the industrial construction industry has a variety of types of projects where piping spools are needed, including chemical plants, power plants, petroleum refineries and other industrial construction plants. Piping work is typically divided into the two stages of pipe spool fabrication and site installation in order to work within the limited space on site and the tight schedule found on job sites.
Most pipe spools are fabricated in fabrication shops where raw pipes are cut down to the exact fittings and connected to their fabrications via welding. Pipe spools are made out of pipes, fittings, flanges and forgings using materials such as stainless steel, carbon steel and alloy steel.
The only disadvantage to pipe spools is that because the spools are made offsite, there is no guarantee that they will fit onsite. When faulty dimensions are given on the isometric, it may lead to several pipe spools needing additional work or the entire process may need to be redone.