A flanged pipe is a type of pipe that has an area on the end that gives it a special function beyond a normal pipe. A flange may be inside or outside the pipe, and it usually allows the pipe to connect to a specific type of system. The flange makes the pipe thicker at the end and may make it wider as well, if the flange is on the outside. The chief reason to use a flanged pipe is to make attaching and removing the pipe from the connected system easier.
There are many types of flanged pipes used in all aspects of plumbing. The most common variety is on everyday household pipes. These pipes have one wide end, the flange, and one standard end. The flanged end is threaded on the inside, and the standard end is threaded on the outside. This allows a second flanged pipe to connect to the first, flanged end to standard end. The flange allows the second pipe to screw in 1 to 2 inches (0.02 to 0.05 meters), creating a practically watertight physical seal.
Outside of normal piping, it is possible to find a flanged pipe in several other areas as well. Most household and industrial water-based devices contain a specialized type of flanged pipe that connects them to the main water system. This pipe creates a seal that is specifically designed for that particular device. Common examples of these types of pipes may be found on toilets, water heaters and boilers.
Industrial piping systems have a different type of flange. These flanged pipes have a wide lip that stands several inches or meters away from the edge of the pipe. These pipes will match up with another pipe of the same design. These two pipes will end up bolted together through holes in the flange. Sometimes a gasket is placed between the two pipes to assure a watertight design, but often the bolting process makes the two pipes fit together so closely that they are physically watertight.
There are several different standards that determine the size and fitting styles of piping. In the United States, the American Natural Standards Institute (ANSI) sets the size for piping and flanges, and it is one of the larger standards used worldwide. In nearly every case, a pipe made to one national standard will not fit a pipe made to another. Since local designs will use local piping, this is usually only a problem in locations where machinery is brought in from elsewhere, like military bases or oil platforms.