Tee fittings in production in accordance with a certain process and principle, to ensure that in actual use to ensure good production quality and guarantee, the geometric dimensions of tee fittings including outer diameter, inner diameter, wall thickness. It is the requirement for packaging. For small pipe fittings, such as export, it is necessary to make wooden cases, about 1 cubic meter. It is stipulated that the number of tee fittings in such cases should not exceed 1 ton. The standard allows suits, that is, large sets and small sets, but the total weight should not exceed 1 ton. For large items, they need to be packed individually. For example, 24 "items must be packed individually. In addition, it is the packaging mark. The mark is to indicate the size, steel grade, batch number and manufacturer's trademark. Steel seal shall be made on the tee fittings, and the packing list, quality guarantee and other documents shall be attached. 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 required tolerance.
The production process of tee fittings is basically the same. The blanking shall be carried out according to different specifications of tee fittings. After blanking, sandblasting is necessary, and the oxide scale on the surface should be removed before forming. Hydraulic bulging is used for forming. There is a mold, the bottom of the mold is straight, and there is a flange hole on the top. After the pipe is put in, the pipe is fixed with hydraulic cylinder, the two sides are filled with liquid to bulge inward, the pipe is extruded into a "convex" shape, and then the convex part is cut from the appropriate position, and the groove is also made. It has to be shot peened twice. Due to the process of processing, there is work hardening, so also need heat treatment. The production process of tee fittings is just like this.
Because most of the tee fittings are used for welding, in order to improve the welding quality, the ends are turned into grooves, with a certain angle and a certain edge. This requirement is also relatively strict. There are regulations on the thickness of the edge, the angle and the deviation range, and there are many more items than the fittings in geometric dimensions. The surface quality and mechanical properties are basically the same as those of pipes. For the convenience of welding, the steel grade is the same as that of the connected pipe. That is to say, all tee fittings should undergo surface treatment, and the oxide scale on the inner and outer surfaces should be sprayed off by shot peening, and then coated with anti-corrosion paint. This is not only for the needs of export, but also for the convenience of transportation and the prevention of corrosion and oxidation in China.
