In a cryogenic liquid cylinder system, where should the gas produced by evaporation from the secondary header enter the supply system?

In a cryogenic liquid cylinder system, the gas produced by evaporation from the secondary header should enter the supply system upstream of the final line regulator. This is essential for maintaining pressure control and ensuring stable gas delivery. By introducing the vapor before it reaches the regulator, you allow the regulator to function effectively, managing the pressure and flow rate of the gas that reaches the point of use.

Placing the gas upstream means it can be mixed appropriately with any existing gas and allows the regulator to expand and decrease the pressure without sudden fluctuations in supply, contributing to a consistent and controlled gas supply. This is critical in medical applications where precise delivery of gases is necessary for patient safety and equipment operation.

Introducing the gas at either the final line regulator or at the secondary header could lead to less control over the pressure and flow, risking the integrity of the system and potentially leading to unsafe conditions. Storing vapor separately in a tank also removes the direct integration with the system, complicating the supply process and potentially leading to inefficiencies or safety concerns.