Elbow flow chart

①Receiving inspection of raw material. It is the first compulsory chain to guarantee good quality. The testing items refer to chemical composition, mechanical capacity and metallographic analysis.
② Cutting raw material. Correctly and strictly controlling cutting size and proportion can ensure moderate cost.
③ Hot forming. In this step the raw material will be put on the pushing machine, then getting the elbow blanks. The temperature and speed of hot forming determine the quality of elbow blank. If the quality of blank is very good which can reduce some cost. So it is very necessary to control and record the temperature and speed of hot forming.
④ Sizing. The shape of elbow blanks that got in hot forming process are not very good. So it is necessary to adjust the shape, at the same time inspecting if the quality of adjusted blank is ok or not after sizing.   
⑤ Heat treatment. The purpose of heat treatment is to eliminate the stress inside of elbow so that the density is more evenly. Carefully recording the temperature of heat treatment and cooling time are the keys.  
⑥ Short blasting. The purpose of short blasting is to remove the rust on the elbow. The size of sandblasting can affect the smooth of elbow surface, if the size is too big will lead to the surface is rough, so it is better to choose small size sand.
⑦ Bevel end machining. The angle of bevel end is different for different standard elbow. Correctly and strictly controlling the machining process to make sure the angle is qualified.
⑧ Coating. Generally the coating is black painting, vanish and anti-rust oil. No matter which type the surface should be smoothly.
The whole production chains are all very important, so the datas of each production step of flange must be recorded in details according to ISO request. It is the guarantee for good quality.