The flange is the second most utilized joining technique in the of welding. Flanges are utilized when joints need disassembling. It gives flexibility for maintenance. Spine Connects the pipe with different equipment and valves. Breakup flanges are included in the pipeline system if regular maintenance is required during plant operation.
A flanged joint is made out of three discrete and independent although interrelated segments; the flanges, the gaskets, and the bolting; which are gathered by one more impact, the fitter. Exceptional controls are required in the choice and use of every one of these components to achieve a joint, which has adequate hole snugness.
Flanged connections versus welded connections
There are no standard protocols are followed for the usage of the flange. It can be used if necessary, for the situation. In a newly built factory is customary to minimize flange connections, because only one weld is needed to connect two pieces of pipe. This saves the costs of two flanges, the gasket, the stud bolts, the second weld, the cost of NDT for the second weld, etc.
One of the main drawbacks of the flange is that it can never be 100% leak proof. Space requirement of every flange is high so the compaction of the entire piping system is limited to an extent. Insulation of flanged pipe systems is more expensive (special flange caps).
Types of flanges used in a piping system
- Welding Neck Flange
- Slip-on Flange
- Socket Weld Flange
- Lap Joint Flange
- Threaded Flange
- Blind Flange
Materials for Flanges
Pipe flanges are produced in all the various materials like hardened steel like stainless steel, cast iron, aluminium, metal, bronze, plastic and so forth however the most utilized material is forged carbon steel and has machined surfaces.
Likewise, flanges, similar to fittings and channels, for explicit purposes some of the time internally equipped with layers of materials of totally unique quality as the flanges themselves, which are “lined flanges”. The material of a flange is essentially set during the decision making of the pipe, regularly we use, a flange is of a similar material as the pipe.
Design and behaviour of bolted joints
Flanges are broadly utilized in numerous industries for various applications. The quantity of flange standards is similarly various. All standards are not equal or proportional. The flange specification `utilized must be suitable for the application. Pipework dealing with risky liquids must fit in with a prescribed quality which must be supported by material and testing certification.
Flanges are the most mainstream connection technique for pipe sizes over DN80 however are not by any means the only one conceivable. Different strategies ought to be considered during the structural/designing procedure. Flanges can be hard split after years of hot task. If joints are not required to be broken routinely, at that point lasting connections should be considered, for example, welding.
Flanges can be manufactured by many methods. The following list starts with the highest quality:
- forged to a finished shape
- cast then “HIPed” (HIP, Hot Isostatically Pressed)
- powder metallurgy
- machined from solid
- machined from plate