The technical requirements for pipe fittings are as follows:

1. 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 length is 1.5d, the radius of curvature must be within the specified tolerance range.
2. Since most of these pipe fittings are used for welding, their ends are beveled with a specific angle and reserved edge to improve welding quality. This requirement is relatively stringent, with clear specifications for edge thickness, angle value and deviation range, adding far more geometric dimension indicators compared with ordinary pipes.
3. The surface quality and mechanical properties are basically consistent with those of pipes. To facilitate welding, they adopt the same steel grade as the connected pipes.
4. All pipe fittings shall undergo surface treatment. The oxide scale on both internal and external surfaces shall be removed by shot blasting, followed by anti-corrosion paint coating. This treatment is required for export purposes, and domestically, it is also implemented to facilitate transportation and prevent rusting and oxidation.
5. There are clear packaging requirements. Small pipe fittings for export shall be packed in wooden boxes of approximately 1 cubic meter, with the total weight of elbows in each box not exceeding one ton. Nest packaging (large fittings containing small ones) is permitted under this standard, while the overall weight shall generally not exceed 1 ton. Large-sized products such as 24-inch fittings must be individually packaged. In addition, packaging marks shall indicate dimensions, steel grade, batch number and manufacturer’s trademark. Steel stamps shall be marked on pipe fittings, accompanied by packing lists, quality guarantee certificates and other relevant documents.