The pump valve castings need certain technical requirements in the process of production. In order to ensure the working performance and mechanical properties of casting parts, the surface of the pump valve casting is not allowed to have cold shut, deformation and repair.
The production of the pump valve casting is a process combined with multiple operation, which includes the following main processes:
1. The production process preparation, according to the part drawing， production batch and delivery time, formulate the production process plan and the craft document, and draw the casting process plan.
2. Production preparation, including preparation of melting materials, molding core materials and shape, core box, sand box and other technical equipment.
3. Modelling and core making.
4. Melting and pouring.
5. Peeling and casting inspection and other main processes.
In the production of the pump valve casting, the principle of high temperature discharging and low temperature pouring should be followed when casting. Because the increase of the metal liquid temperature is conducive to the complete melting of inclusions, slag flotation, easy to clear slag and degassing, reduce the slag and porosity of the castings. Using lower pouring temperature, it is beneficial to reduce the gas solubility, liquid shrinkage and baking of high temperature metal liquid to the cavity surface, so as to avoid defects such as porosity, burnt-on sand and shrinkage cavity. Therefore, under the premise of ensuring full mold cavity, the lower pouring temperature is adopted as far as possible.
The production of the pump valve casting is to melt the metal to make it have the fluidity, and then pour into the mold cavity with a certain shape. Under the action of gravity or external force ( pressure, centrifugal force, electromagnetic force, and so on ), the cavity is filled. This is a metal forming method which is cooled and solidified into the casting. The casting is generally used as a rough machining to become a part. However, many castings can meet the design accuracy and surface roughness requirements of the parts without cutting, and can be used as parts directly.http://www.pump-casting.com/