In addition to the selection of valves to consider the corrosive properties of the medium, flow characteristics, connection form, the temperature, and pressure of the medium is an important parameter.
Also need to consider the relationship between the valve temperature and pressure: the use of valve temperature and pressure have a certain intrinsic link, but also affect each other.

Among them, the temperature is the dominant factor, a certain pressure of the valve is only adapted to a certain temperature range valve temperature changes can affect the use of the valve pressure.
For example, a cast steel valve nominal pressure of PN100; when the medium working temperature of 200 ℃, its the maximum working pressure of 10MPa; when the medium working temperature of 400 ℃, it’s the maximum working pressure of 5.4MPa; when the medium working temperature of 450 ℃, it’s the maximum working pressure of 4.5MPa.