Technical Requirements for Pipe Fittings
The technical requirements for pipe fittings are as follows:
Geometric dimensions include outer diameter, inner diameter and wall thickness. It is also required to control the radius of curvature. If the radius is 1.5d, the radius of curvature must be within the required tolerances. As most of these pipe fittings are connected to pipes by welding, in order to improve the quality of welding, the end of the pipe fitting should be cut into a groove, leaving a certain angle with a certain edge; this requirement is relatively stringent and there are regulations for edge thickness, angle and range of variation. The surface quality and mechanical properties of pipe fittings are basically the same as those of the tubes. The steel grade of pipe fitting is the same as the connected pipe in order to facilitate welding. There should be surface treatment for all pipe fittings, removing the inner and outer scales by shot blast and then coating with anti-corrosion paint. This process is not only for exporting to other countries, but also for preventing oxidation rust during domestic transportation. There are also some requirements for packing. For small size
pipe fittings, we need to make a wooden box which is about 1 cubic meter and the total weight of pipe fittings inside should not exceed one ton; this standard allows a mixed package, that is, putting the small size pipe fittings into the big ones, but the total weight can not be over 1 ton. For big size pipe fittings, we need to have a single package, for example, pipe fittings with size of 24 inch should be packed alone. In addition, the marks on packages, is to indicate the size, steel number, batch number and manufacturer trademark. Stamp the pipe fitting with steel seal along with documents of packing list and written warranty.