Feature 1: There is a weld seam on the butt weld elbow. After the welding construction operation is completed, the weld elbow needs to be rust-proof or anti-corrosive according to the actual situation or the external environment of the pipeline to avoid corrosion or corrosion of the elbow at the weld. -- This process allows us to clarify the quality of the weld elbow before use.

Feature 2: Usually the welding elbow is welded at the pipeline construction site. This is because the welding standards of various pipelines are different, and it is necessary to carry out on-site welding according to the pipeline weld grade. Field welding is required for different pipe weld grades, which is another feature of the weld elbow.

Feature 3: The butt weld elbow is mainly used to connect two sections of different end face radius, or to change the diameter of the pipeline. This type of elbow generally needs to be produced according to specific engineering requirements or specific drawings. In addition to meeting the requirements of the pipe diameter, the specific conditions of the pipe must also be considered, such as pipe delivery pressure, fluid viscosity, wear, corrosion, fluid transportation. Temperature and other factors. It has certain pertinence and usability, which is another important construction and use feature for the welding elbow.

Technical requirements for butt welds

Geometric dimensions include outer diameter, inner diameter, and wall thickness. It is also required to control the radius of curvature. For example, if the radius is 1.5D, the radius of curvature must be within the required tolerance. Since most of these pipes are used for welding, in order to improve the quality of the welding, the ends are all turned into bevels, leaving a certain angle with a certain edge. This requirement is also stricter, how thick the edges are, what the angle is and the range of deviation. There are provisions, the geometry is much more than the pipe fittings. The surface quality and mechanical properties are basically the same as the tube. For the convenience of welding, the steel grade of the pipe to be connected is the same. Fourth, all the pipe fittings must be surface treated, and the iron oxide skin on the inner and outer surfaces is sprayed by shot peening, and then coated with anticorrosive paint. This is not only for export needs, but also for the purpose of facilitating transportation to prevent corrosion and oxidation in the country. The fifth is the requirement for packaging. For small pipe fittings, such as export, it is necessary to make wooden boxes, about 1 cubic meter. The number of elbows in such boxes is about no more than one ton. The standard allows suits, that is, large sets. Small, but the total weight can not exceed 1 ton. For large pieces, a single package, like 24 inches, must be packaged individually. The other is the packaging mark, which is to indicate the size, steel number, batch number, and manufacturer's trademark. The pipe fittings should be stamped with documents such as packing list and warranty.