Low temperature globe valves are suitable for regulating system of storage equipments for low temperature fluids, having features of flexible operation, reliable sealing, etc. The globe valves can be also used for other low temperature or copious cooling media. Normal temperature globe valves refer to the globe valves used for the media whose temperature ranges from -40℃ to 500℃. The materials of body are also different. Low temperature globe valves refer to the globe valves used for low temperature fluid media whose temperature ranges from -196℃ to -150℃.
Low temperature globe valves have extremely low operating temperature. So when design this kind of valves, besides following design principles of common valves, some particular requires also should be noticed.
Design requirements for low temperature globe valves:
1. Globe valves should have capacity that works for a long time for low temperature media or under low temperature.
2. Valves cannot become a remarkable heat source of low temperature system. Besides reducing thermal efficiency, overmuch heat makes inner media evaporate hastily, causing unusual pressure rising and resulting in danger further.
3. Low temperature should not have harmful impact on handwheel operation and sealing performance of packing.
4. Composite members of valves which contact directly with low temperature media should have explosion and fire proofing structure.
5. If composite members of valves cannot be lubricated under low temperature, some measures should be taken to prevent friction pieces from being bruised.
Moreover, several factors should be taken into consideration when choosing materials for low temperature globe valves:
1. Minimum operating temperature.
2. Mechanical properties of metals valves are used to ensure operating conditions under low temperature, especially impact toughness, relative elongation and structure stability.
3. Metal materials should still have good wearing resistance under low temperature or the conditions without oil lubrication.
4. Have good corrosion resistance.
5. Welding performance of materials should be considered when welding connection is adopted.