Flange is a type of connector that joins pipes, pumps and valves. Flanges allow you for the user to gain access to the pipe and check, clean, or change the system. Create flanged joints by bolting together two flanges, with a gasket sandwiched between them, then welding or screwing the two pieces. Be sure to read to see the American Society of Mechanical Engineers (ASME) instructions before working with flanges. There are not many flange styles that can be put together. For example, you cannot mix a flat face the flange with an elevated face Flange. The video on this page covers flat and grooved flanges. The distinction between the types of flanges as well as how they can be combined helps you complete a a safe piping job. The ASME website provides a checklist of recommended piping flanges. The organization has put in the work to research what combinations of pipe Flange, flange distributor etc. will work well together. rssb41x473.