General Description: Leakage from the valve packing gland is often a problem for environment protection and sometime it is quite dangerous if such leakage is from a hazardous fluid or gas. KOS bellows sealed valves are designed with a bellows cartridge which welded to the valve bonnet and stem, when the stem up & down movement makes the bellows expands & compress. Therefore there is no sliding or rotating seals through which process fluid can leak.