Welding refers to the uniting or fusing of pieces by using heat or compression so that the pieces form a continuum. The source of heat in welding is usually an arc flame produced by the electricity of the welding power source. Arc-based welding is called arc welding.
The fusing of the pieces can occur solely based on the heat produced by the arc so that the welding pieces melt together.
Usually, a filler metal is melted into the welding seam, or weld, either using a wire feeder through the welding gun (MIG/MAG welding) or by using a manual-feed welding electrode. In this scenario, the filler metal must have approximately the same melting point as the material welded.
Before beginning with the welding, the edges of the weld pieces are shaped into a suitable welding groove, for example, a V groove. As the welding progresses, the arc fuses together the edges of the groove and the filler, creating a molten weld pool. That is why most of our products are designed to have certain degree beveling for most pipe fittings.
For the weld to be durable, the molten weld pool must be protected from oxygenation and effects of the surrounding air, for example with shielding gases or slag. The shielding gas is fed into the molten weld pool with the welding torch. The welding electrode is also coated with a material that produces shielding gas and slag over the molten weld pool.
The most commonly welded materials are metals, such as aluminum, mild steel, and stainless steel.
The following is our equipment of Auto-welding machine and welding pictures:
Commonly the butt welding pipe fittings includes elbows,tees,reducers,caps,paddles,stub ends,crosses,hot induction bends.
In ASME/ANSI standard,butt welding pipe fittings technical requirements are specified in the standard ASME/ANSI B16.9,including all the types of pipe fittings.In En standard,it is EN10253 standard for the butt welding pipe fittings.In JIS,DIN,Gost standard,different type of butt welding fittings are in different standard number.For example,JIS B2311,B2312,B2313 or GOST 17373,GOST 17375,GOST 17376,GOST 17378 etc.There are also some other standards about butt welding pipe fittings like:MSS SP-43,MSS SP-75,ASME B16.49.
The butt welding pipe fittings could be seamless or welded in body.The seamless butt welding fitting means there is no welding seam on the body of the fitting when manufacturing,it is usually produced from the seamless steel pipes.The welded butt welding pipe fitting means there is a welding seam on the body of the fitting when manufacturing,usually,it is produced from the welded pipes or formed steel plates.Commonly the butt welding pipe fittings nominal size more than 26 inchs are welded butt welding pipe fittings,and smaller butt welding fittings are seamless one.
The materials of butt welding pipe fittings could be carbon steel,stainless steels or alloy steels,and other alloys like the nickel-base alloy,titanium alloy.In ASME/ANSI standard,carbon steel material butt welding pipe fitting is A234 WPB pipe fittings or ASTM A860 WPHY pipe fittings.