[ oxygen ]
Fig. 6. Recommended gas velocity limits as a function of pressure
• ASTM International( formerly the American Society for Testing and Materials) – ASTM G88: Standard Guide for Designing Systems for Oxygen Service
• Asia Industrial Gases Association – AIGA 021 / 12: Oxygen Pipeline and Piping Systems
Adherence to these standards and guidelines should follow the requirements for the relevant region, though they all share common principles, including design philosophies; material compatibility; gas velocity and pressure considerations; plant siting considerations; piping, valve, and equipment selection; cleaning of equipment for installation; and installation inspection.
A visual example of such a guideline can be found in EIGA Doc 13, which outlines recommended gas velocity limits based on pressure. It states that, even at lower pressures, for impinging gas flows, gas velocities should not exceed 30 m / s, and at pressures above 15 bar, velocity should decrease.
Conclusions
Oxygen-enriched environments, such as those within an electrolyser plant, present significant risks to system designers, installers, and operators due to their potential to cause catastrophic events. The considerations required for oxygen compatibility differ from those for other gases commonly used in industry. It is imperative that suitable solutions are implemented and that oxygen-specific competencies and components are sought to achieve those solutions.
The key components for most electrolyser installations on the oxygen side are the gas-liquid separator vessel and any filter or coalescing media used to further improve water return volumes to the stack.
Parker has a proven track record of delivering gas-liquid separator vessels for oxygen service, employing carefully chosen materials and design strategies. Construction materials, material thicknesses, and gas velocities are all carefully
48 Hydrogen Tech World | Issue 21 | April 2025