Workers carefully pour the molten metal into the mold. During the pouring process, attention should be paid to the pouring speed and method to avoid defects such as pores and slag inclusions. After the poured metal liquid cools and solidifies in the mold, workers open the mold and take out the flange casting. For sand casting, the sand mold must be broken; for metal mold casting, the casting can be taken out directly. Clean the sand and burrs on the surface of the flange casting, and then perform machining, such as machining the sealing surface and bolt holes, to meet the requirements of the finished flange.