The thick and hot spots formed in the casting structure of the pump valve can be rapidly solidified to a certain extent, artificially causing a basic balance of the temperature field throughout the machine tool casting. The use of internal and external cold iron, local use of heat storage zircon sand, chromite sand or special coatings.
The valve casting uses its reasonable process equipment. The entire product's inner runner will be located at the relatively thin wall of the machine tool casting, so that the molten metal that first enters the thick-walled part will be solidified first, and the thin-walled part will be solidified later, so that the basic balance will be reached everywhere. solidification. For a machine tool casting with a uniform wall thickness, multiple runners and vents are used. In sprue, scattered and uniform, so that the overall heat balance. The vents are thin and numerous, which means that the exhaust gas is smooth and has a cooling effect.
The pump valve casting can effectively use the molding material with a relatively large heat storage capacity, and it is extremely important for the production of the anti-wear product by the lost foam mold during use. Chromite sand replaces other sand species such as quartz sand, which have low heat storage, and will achieve good results.
The low-temperature rapid firing of the pump valve castings enables the open pouring system to be used when it is in use. This allows the molten metal to fill the casting mold quickly, smoothly and evenly. The cast iron of the ductile iron machine has high strength, surface hardness ≧ 90, and the rigidity of the sand box. Large, it is beneficial to eliminate shrinkage.http://www.pump-casting.com/