The scope of use of cast iron valves is generally specified as follows:
When used for rated pressure PN≤1.0MPa, working temperature is -10~200℃, working medium is water, sea water, steam, air, gas, oil, etc., gray cast iron valves generally choose the grades HT200, HT250, HT300, HT350.
When the rated pressure is PN≤2.5MPa, the working temperature is -30~300℃, and the working medium is water, sea water, steam, air, gas, oil, etc., malleable cast iron valves generally choose KTH300-06, KTH330-08, KTH350-10 type .
When the rated pressure PN≤4.0MPa, the working temperature is -30~350℃, and the working medium is water, seawater, steam, air, gas, oil, etc., the grades QT400-15, QT450-10, QT500- 7 ductile iron valves.
The second is the cast steel valve.
Due to the use of different steel grades, the suitable medium for steel valves is also very different. Although steel valves are expensive, because steel is a plastic body, solenoid valve coils have a wide range of applications and can be used in various media, such as tungsten. , Saturated steam and hot steam, high and low temperature oil, liquefied gas, strong corrosive medium, etc., so it is widely used.
Because carbon steel has excellent mechanical properties and comprehensive performance, it can be used in a wide range, usually including the working conditions of cast iron valves and bronze valves (widely used below -180°C). The main equipment, equipment supply solenoid valves and pipelines generally use solid and reliable steel valves. For flammable gas, liquid, toxic gas, liquid, flammable medium, compressed gas, liquefied gas, power equipment pipeline and other similar occasions, steel valves should be used.
When the working temperature is below zero, special carbon steel and low-nickel alloy steel can be used, but not in low-temperature areas. Valves made of this material can be used for media such as seawater, carbon dioxide, acetylene, propylene and ethylene.