A butt welding pipe fitting means the a pipe fitting which has the connecting end for butt welding.
The butt welding pipe fittings are used to connect with pipes or fittings with a same size and same schedule butt welding ends. The ends of the butt welding pipe fittings are plain ends or bevel ends. 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.