Casting valves: that is, the metal is melted into a liquid that meets the requirements and poured into the specified valve model, after cooling and solidification, clearing treatment can be obtained with a predetermined shape, size and performance of the valve castings, which is the entire process of casting valves.
The main advantage of casting is that the casting production of blanks at low cost, for complex shapes, especially with complex internal cavity parts, more to show its economy. At the same time it has a wider adaptability, and has a better overall mechanical properties. But the casting production of materials and equipment required more, and will produce dust, harmful gases and noise and environmental pollution.
Forging valve is the use of forging machinery on the metal valve billet pressure, so that it produces plastic deformation in order to obtain a certain mechanical properties, a certain shape and size of the forging processing methods. Forging according to the molding method can be divided into open forging (free forging) and closed mode forging. According to the deformation temperature forging can be divided into hot forging, warm forging and cold forging. Forging material is mainly a variety of components of carbon steel and alloy steel, followed by aluminum, magnesium, titanium, copper and its alloys. The original state of the material is bar, ingot, metal powder and liquid metal. The ratio of the cross sectional area of the metal before deformation to the die sectional area after deformation is known as forging ratio.
Through forging can clean up the cast state of the metal loose, welded holes, the mechanical properties of forgings are generally better than the same material castings. Mechanical high load, severe working conditions of the important parts, in addition to the shape of the simpler available rolled sheet, profile or welded parts, more forging. Correctly selected forging than to improve product quality and reduce costs have a great relationship.
Casting valves is cast into the valve, the general casting valve pressure levels are relatively low (such as PN16, PN25, PN40, but there are also high-pressure, can be up to 1500Lb, 2500Lb, most of the caliber are DN50 or more. Forged valves are forged, generally used in high pressure level of the pipeline, forged valves to small diameter, generally in the DN50 below.