Butt Welding Elbow Forging process , A234 WPB,Carbon steel

Butt Weld elbow is a kind of elbow which is formed by hot pressing or forging technology, connection method is through the elbow and steel pipe butt welding, the use of resistance heat to the two workpiece along the entire end of the welding together, usually has resistance to welding and flash butt welding 2 methods, high productivity, easy to automate, so has been widely used.

Butt welding elbow generally have 45 degrees elbow, 90 degrees elbow, 180 degrees elbow, and other materials have carbon steel, alloy steel and stainless steel. General welding elbow Welding in the pipeline construction site, which is due to different types of pipe welding standards and the need for on-site welding by pipe weld grade.

Weld in butt welded elbow.

butt weld fitting elbow A234 WPB

Material Division of Butt Weld Elbow

Carbon steel: Astm/asme A234 WPB, WPC
Alloy: Astm/asme A234 WP 1-wp 12-wp 11-wp 22-wp 5-wp 91-wp911, 15mo3 15CrMoV, 35CrMoV
Stainless Steel: ASTM/asme A403 WP 304-304l-304h-304ln-304n
                        　　Astm/asme A403 WP 316-316l-316h-316ln-316n-316ti
                               Astm/asme A403 WP 321-321h ASTM/ASME A403 WP 347-347h
Low Temperature steel: Astm/asme A402 WPL3-WPL 6
High-performance Steel: Astm/asme A860 WPHY 42-46-52-60-65-70

Butt Carbon Steel Elbow Factory Equipment Machine：

Elbow Factory Equipment Machine	Groove machine	Push machine
Heat Treatment furnace	Three-tee extrusion machine	Pressing machine

Elbow welding operation is based on the external environment or pipe rust or corrosion treatment of the actual situation completed, in order to avoid corrosion or corrosion in the weld elbow, the elbow life caused by short. Before the elbow welding, in order to avoid welding deformation, the entire side elbow group is at the end of the tile, stainless steel curved plate and keel reinforcement. According to the traditional welding method needs argon arc welding, considering the cost of welding, small waist shrimp diameter, argon is difficult, the above factors, welding by the internal and external two welders symmetrical welding, solve the problem of argon, and modelling is also very good.

Argon arc welding process is adopted.

Welding electrodes are made by and wire selection: Low-level welding using Argon arc welding. Before welding operation, brush chalk, chalk on the left and right sides of the weld area to prevent splash adhesion on the surface of the pipe, and the use of small current before welding. Multilayer, multi-channel, continuous welding. After the whole welding, welded joints and splash welding elbow surface on the welding pad for polishing, nondestructive testing, weld inside and outside the surface.

Pickling and pickling passivation elbow transport to the installation site after on-site installation work.

The technical requirements of butt welding elbow

Geometric dimensions include outer diameter, inner diameter, and wall thickness. It is also required to control the radius of curvature. For example, the radius length is 1.5D, then the radius of curvature must be within the desired tolerance range. Since most of these pipes are used for welding, in order to improve the quality of welding, the end of the Cheng Chengpo mouth, leaving a certain angle, with a certain edge, this requirement is also relatively strict, the edge is thick, the angle for the number and deviation range have provisions, the geometrical size of a lot more than pipe. The surface quality and mechanical properties are basically the same as the tubes.

For the convenience of welding, the steel grades of the connected pipes are the same. Four, that is, all the fittings must undergo surface treatment, the internal and external surface of the iron oxide skin through shot peening treatment, and then coated with anti-corrosion paint. This is not only for export needs, moreover, in the domestic also in order to facilitate transport to prevent corrosion oxidation, to do this work. Five, is the packaging requirements, for small pipe fittings, such as exports, need to do wooden cases, about 1 cubic meters, the provision of such boxes in the number of elbow can not be more than a ton, the standard allows a suit, that is, large sets of small, but the total weight can not generally exceed 1 tons For large pieces to be a single package, like 24〃 must be a single package. The other is the packaging mark, marking is to indicate the size, steel number, lot numbers, manufacturers trademarks.

Stamped on the fitting, with the packing list and quality assurance documents.