Geometry includes the outside diameter, inside diameter, and wall thickness. It is also required to control the radius of curvature. For example, if the radius is 1.5d, then the radius of curvature must be within the required tolerance. Since most of these fittings are used for welding, in order to improve the welding quality, the ends are car-grooved, leaving a certain angle, with a certain edge, this requirement is also more strict, the edge is thick, the angle is how much and the deviation range There are provisions that have many more geometric dimensions than fittings. The surface quality and mechanical properties are basically the same as the tubes. For welding convenience, the steel type of the pipe to be connected is the same. The fourth is that all the pipe fittings must be surface-treated. The inner and outer surface oxide scales are sprayed off by shot blasting and then painted with anti-corrosion paint. This is not only for export purposes, but also for the convenience of transportation in China to prevent rust oxidation. Fifth, the requirements for packaging, for small pipe fittings, such as exports, it is necessary to make wooden boxes, about 1 cubic meter, and the number of elbows in such boxes should not exceed approximately one ton. This standard allows suits, ie large sets of Small, but the total weight cannot exceed 1 ton. For large parts, they must be individually packaged, like 24′′, they must be individually packaged. The other is the packaging mark. The mark is to indicate the size, steel number, lot number, and manufacturer’s trademark. The pipe should be stamped with a packing list. And warranty documents and other documents.