Casting valve is cast into the valve, the general casting valve pressure grades are lower (such as PN16, PN25, PN40, but also have high pressure, can to 1500Lb, 2500Lb), the caliber of most of the DN50 above.
Forging valves are forged, are generally used in the high grade of the pipe, the caliber is small, generally in the DN50 below. Casting valves can have more flexible options on the material, from gray iron, ductile iron to ordinary carbon steel, alloy steel to stainless steel, copper alloy, titanium alloy, and to facilitate the casting of complex runner and marker, etc., but due to the characteristics of casting itself, casting defects such as pores, sand, shrinkage/pine limit the pressure of the casting valve grade, The processing allowance is big, the yield is low.
There are not too many restrictions on size, small size can be lost wax casting, a large number of available EPC casting, and then a larger amount of sand can be cast. The forging valve material has the limitation, the processing performance is good, because the internal flaw low yield high (does not include the processing flaw), the cost is high, may forge the simple flow path the high pressure valve.