Forming a valve sphere There are several ways to form the next ball has introduced three different methods: 1. casting method: This is a traditional processing methods, it requires a complete melting, casting and other equipment, but also require more large factories and more workers, investment, process more complex production process, and pollution of the environment, workers' skill levels of each process directly affect the quality of the product, the ball capillary leak still can not completely solve the problem, but the rough large allowance, waste, often found in the process of casting defects due to scrap it, to make the product cost increases, quality can not be guaranteed, this method should not be used factory. 2. forging method: This is another method used by many domestic enterprises valve, which has two processing methods: one is to use round off the heating spherical solid forged blanks, and then machining. The second is the cutting in a circular stainless steel plate on large presses molded to give hollow hemispherical blank, and then welded into ball blank was machined to a high material utilization of this method, but it required a high-power Presses and furnace and argon arc welding equipment, is expected to invest 3 million yuan needed to form productive, this method is not suitable for the situation of our factory. 3. Spinning method: metal spinning method is a little advanced, non-cutting processing methods, belongs to the new branch pressure processing, which combines the forging, extrusion, rolling and rolling and other technological features, with high material utilization ( up to 80-90%), saving a lot of processing time (1-5 minutes shaping), after spinning material strength can be doubled. Due to spinning, the rotary small-area contact with the workpiece, the metal material obtained in two or three to a compressive stress state, easily deformed, lesser power, the unit can obtain a higher contact stress (up to 25- 35Mpa), therefore, light weight, the total power required is small (less than press 1 / 5-1 / 4), has been recognized as foreign valve industry is an energy sphere processing program, but also for in the processing of other hollow rotating body parts. Spinning technology in foreign countries has been widely used and rapid development, technology and equipment are very mature and stable, and to achieve mechanical, electrical, fluid integration of automatic control. Currently, spinning technology in China has also been considerable development, has entered the stage of practical promotion.