flange fitting
Flanges are relatively simple mechanical connectors that have been used successfully for high-pressure piping applications. They are well understood, reliable, cost-effective, and readily available from a wide range of suppliers. In addition, the moment-carrying capacity of flanges is significant compared to other mechanical connectors. This is an important feature for systems that experience pipe-walking or lateral buckling from temperature and pressure variations (e.g. deep water lines). Flanges can be designed to meet a wide range of application requirements such as high-temperature and corrosion resistance.
Blind flanges are round plates with no center hold used to close the ends of pipes, valves, or equipment. They assist in allowing easy access to a line once it has been sealed. They can also be used for flow pressure testing. Blind flanges are made to fit standard pipes in all sizes at higher pressure ratings than other flange types.
Lap joint flanges are used on piping fitted with lapped pipe or with lap joint stub ends. They can rotate around the pipe to allow for an easy alignment and assembly of bolt holes even after the welds have been completed. Because of this advantage, lap joint flanges are used in systems requiring frequent disassembly of the flanges and pipe. They are similar to slip-on flanges, but have a curved radius at the bore and face to accommodate a lap joint stub end. The pressure ratings for lap joint flanges are low, but are higher than for slip-on flanges.