Causes of Leakage in Cryogenic Valves.

There are two main situations, one is internal leakage; the other is external leakage.

Endoleak

The main reason for the internal leakage of the valve is the deformation of the sealing pair at low temperature. When the temperature of the medium drops to the point where the material undergoes a phase change, the volume changes, causing the original high-precision grinding sealing surface to warp and deform, resulting in poor low-temperature sealing.

Leakage

Leakage of the valve: one is that when the valve and the pipeline are connected by flanges, the leakage is caused by the asynchronous shrinkage of the connecting pads, connecting bolts, and connecting materials at low temperatures. Therefore, the connection method between the valve body and the pipeline can be changed from a flange connection to a welded structure to avoid low temperature leakage. The second is the leakage at the valve stem and packing.