Pump valve casting is a less cutting or no cutting casting process in the process of production.It can effectively produce heat - resistant alloy parts such as leaves, impeller, and nozzle, etc.The casting of pump valve is used for casting of various kinds and kinds of alloy, and the precision and surface quality of casting is higher than other casting methods.
Pump valve casting is made with fusible materials meltability model, on which the coated with several layers of tailor-made refractory coating, after drying and hardening type to form a whole shell, reoccupy steam or hot water from the melt in the shell model, and then put type shells in the sand, dry sand by filling in all round its modelling, finally will be cast into the furnace after high temperature roasting (such as high strength shell, can need not modelling and will release the shell directly after roasting), cast type or shell after roasting, in which take the pump valve casting pouring molten metal.
The pump valve casting quality requirements
1. The chemical composition and mechanical properties of the main body of the pump valve are in line with the requirements of the relevant material standards.
2. The deviation of the shape and size of the valve body is in accordance with the requirements of the drawing.
3. The body casting non-machining surface shall be smooth, smooth, non-stick sand, no oxide skin, no porosity, no sand, no cracks and other defects.The body casting marks are clear and the sprue and the riser shall be flush with the castings of the body.
4. All parts of the valve should be connected securely and without loosening.
5. The test results of pressure test and sealing performance of valves meet the requirements of the relevant test standards.
6. The operation of valve shall be free of card resistance under the conditions of nominal pressure and specified pressure.
7. Valve body casting has certain operation times and service life.http://www.dmgcastings.com/