The end all solution for LCO2/LN2 cooling. We have switched from Swagelok PRV's because of temperature ratings are only at -40F. These are CRV's(Cryogenic Relief Valves) that are used for all Dewars, rated down to -320F. The reason Columns implode/explode are because PRV's are not rated for cryo use, the seals freeze and do not relieve. Help us put a stop to implosions.