Effect Of Temperature And Pressure On Butterfly Valve Performance
Many customers send us inquiries, and we will reply asking them to provide the medium type, medium temperature and pressure, because this not only affects the price of the butterfly valve, but is also a key factor affecting the performance of the butterfly valve. Their impact on the butterfly valve is complex and comprehensive.
1. Effect of Temperature on Butterfly Valve Performance:
1.1. Material Properties
In high-temperature environments, materials such as butterfly valve body and valve stem need to have good heat resistance, otherwise the strength and hardness will be affected. In a low temperature environment, the valve body material will become brittle. Therefore, heat-resistant alloy materials must be selected for high-temperature environments, and materials with good cold-resistant toughness must be selected for low-temperature environments.
What is the temperature rating for a butterfly valve body?
Ductile iron butterfly valve: -10℃ to 200℃
WCB butterfly valve: -29℃ to 425℃.
SS butterfly valve: -196℃ to 800℃.
LCB butterfly valve: -46℃ to 340℃.
1.2. Sealing Performance
High temperature will cause the soft valve seat, sealing ring, etc. to soften, expand and deform, reducing the sealing effect; while low temperature may harden the sealing material, resulting in a decrease in sealing performance. Therefore, in order to ensure sealing performance in high or low temperature environments, it is necessary to select sealing materials suitable for high temperature environments.
Following is the operating temperature range of the soft valve seat.
• EPDM -46℃ – 135℃ Anti-aging
• NBR -23℃-93℃ Oil Resistant
• PTFE -20℃-180℃ Anti-corrosion and chemical media
• VITON -23℃ – 200℃ Anti-corrosion, high temperature resistance
• Silica -55℃ -180℃ High temperature resistance
• NR -20℃ – 85℃ High elasticity
• CR -29℃ – 99℃ Wear-resistant, anti-aging
1.3. Structural strength
I believe everyone has heard of the concept called "thermal expansion and contraction". Temperature changes will cause thermal stress deformation or cracks in butterfly valve joints, bolts and other parts. Therefore, when designing and installing butterfly valves, it is necessary to consider the impact of temperature changes on the structure of the butterfly valve, and take corresponding measures to reduce the impact of thermal expansion and contraction.
1.4. Changes in flow characteristics
Temperature changes may affect the density and viscosity of the fluid medium, thereby affecting the flow characteristics of the butterfly valve. In practical applications, the impact of temperature changes on flow characteristics needs to be considered to ensure that the butterfly valve can meet the needs for regulating flow under various temperature conditions.
2. Effect of Pressure on Butterfly Valve Performance
2.1. Sealing performance
When the pressure of the fluid medium increases, the butterfly valve needs to withstand a greater pressure difference. In high-pressure environments, butterfly valves need to have sufficient sealing performance to ensure that leakage does not occur when the valve is closed. Therefore, the sealing surface of butterfly valves is usually made of carbide and stainless steel to ensure the strength and wear resistance of the sealing surface.
2.2. Structural strength
Butterfly valve In a high-pressure environment, the butterfly valve needs to withstand greater pressure, so the material and structure of the butterfly valve must have sufficient strength and rigidity. The structure of a butterfly valve usually includes valve body, valve plate, valve stem, valve seat and other components. Insufficient strength of any one of these components may cause the butterfly valve to fail under high pressure. Therefore, it is necessary to consider the influence of pressure when designing the butterfly valve structure and adopt reasonable materials and structural forms.
2.3. Valve operation
The high-pressure environment may affect the torque of the butterfly valve, and the butterfly valve may require greater operating force to open or close. Therefore, if the butterfly valve is under high pressure, it is best to choose electric, pneumatic and other actuators.
2.4. Risk of leakage
In high-pressure environments, the risk of leakage increases. Even small leaks can lead to wasted energy and safety hazards. Therefore, it is necessary to ensure that the butterfly valve has good sealing performance in high-pressure environments to reduce the risk of leakage.
2.5. Medium flow resistance
Flow resistance is an important indicator of valve performance. What is flow resistance? It refers to the resistance encountered by the fluid passing through the valve. Under high pressure, the pressure of the medium on the valve plate increases, requiring the butterfly valve to have higher flow capacity. At this time, the butterfly valve needs to improve flow performance and reduce flow resistance.
In general, the impact of temperature and pressure on butterfly valve performance is multifaceted, including sealing performance, structural strength, butterfly valve operation, etc. In order to ensure that the butterfly valve can operate normally under different working conditions, it is necessary to select appropriate materials, structural design and sealing, and take corresponding measures to cope with changes in temperature and pressure.