The gasket of large flange pipe is a ring made of high strength material which can produce plastic deformation.  Most of the gaskets are cut down from non-metallic plates, or are made by professional factories according to the specified scale, its material is asbestos rubber sheet, asbestos board, polyethylene board and so on;  Also useful thin metal plate (iron sheet, stainless steel) asbestos and other non-metallic materials wrapped up made of metal gasket;  There is also a winding gasket made of thin steel tape and asbestos tape wound together.  

 
So how is the core of large flange fittings made?  Take the common national standard elbow for example, if it is to manufacture the long radius elbow, it is necessary to select the product specifications first, and then put forward the pipe material, and then process according to the calculated diameter expansion rate.  After the completion of the basic processing, also need to carry out a series of finishing work on the product, that is to say, the appearance of the product and other details for further treatment, which mainly includes shot peening, steel word, appearance spraying and packaging work.  
 

All the common flange fittings of large flange fittings include flat welding flange fittings and butt welding flange fittings.  Flat welded flanged pipe fittings have poor rigidity and are suitable for the occasions of pressure P ≤4MPa;  Butt welding flange pipe fittings, also known as high neck flange pipe fittings, more rigid, suitable for high pressure and temperature occasions.  There are three types of sealing face of flange pipe fittings: plane sealing face, suitable for the occasion of low pressure and medium;  Concave and convex sealing surface, suitable for slightly higher pressure occasions;  Tenon groove sealing surface, suitable for flammable, explosive, toxic medium and high pressure occasions.  Different properties of flanged pipe fittings pipe fittings have outstanding product functions in different fields, and the effects will be different when the occasion and space are different.