Considering the thermal strength, the problem of severe thermal expansion and contraction causes the gap between the guide and the rotating gap of the valve plate to be reduced or even become excessive due to expansion, thereby being stuck. Therefore, the influence of temperature and pressure on the mechanical strength of the material must be considered in the design and selection. (For example, under the high temperature conditions of the boiler feed water system and the superheated bypass system, the conventional valve body and trim materials are not applicable.) So, how is the high temperature control valve divided?

High temperature regulating valve means medium temperature ≥200°C, which can be divided into three categories: 200°C～450°C, 450°C～700°C and 700°C. Therefore, the valve body and valve of this valve electric device under high temperature conditions What are the requirements for the selection of internal parts?

1. The temperature of the valve body is 200 °C ~ 450 °C. The valve body is made of SUS304 material. The valve inner part is made of Steilai alloy surfacing and hardened.

2, the temperature is between 450 ° C ~ 700 ° C valve body is usually chrome molybdenum steel material.

3, the temperature is higher than 700 ° C valve body is usually selected SUS310S type stainless steel, and the carbon content must be controlled between 0.04% ~ 0.08%.

4. For higher temperatures, it is recommended to use non-metallic heat-resistant materials (can be used for high temperature conditions at 1200 °C) or special high temperature resistant and high strength alloys (such as engine combustion).