When we mention Cryogenic Valves, usually it refers to service temperature from -46 °C to -196 °C, and extended stem or extended bonnet.

Here are the advantages of extended stem or bonnet: 
1.The extended stem/bonnet can protect the stuffing box from low temperature and make sure low leakage here.
2.This design can also facilitate rapid replacement of main valve parts, where you don’t need to disassemble the valve body, all you need to do is just removing the cover to replace the parts.

What could be the disadvantages of extended stem or bonnet? 
First, it requires larger room for installation. Second, the stem or the bonnet will easily get bent or deformed due to moment by the actuator or the inappropriate calculation of its length. 

Dervos is a leading industrial valve maker and trader in China, specializing in the production of cryogenic valves. In addition to those in rare conditions, we also produce other industrial pipeline valves, such as trunnion-mounted ball valves, shut-off pig valves and so on. To learn more about our industry-leading products, contact us today.