Industrial Equipment for Oxygen Service: An Overview
Industrial oxygen systems involve all equipment used in oxygen service pipelines. This includes equipment used to produce, store, or circulate — or that otherwise use/come into contact with — liquid or gaseous oxygen. Given the role of oxygen systems in both manufacturing and the various energy sectors (including petroleum refineries, power plants, and natural gas systems), equipment used for oxygen service is often subject to near-continuous operation and high-volume and high-pressure flow. Under these conditions, accidental ignition in oxygen service pipelines can prove not only financially costly but also lethal to personnel and damaging to critical public-sector services.
Oxygen is not flammable, yet as the oxygen concentration and pressure in an environment increases, flammable materials in that environment become more prone to ignition (ignite more easily and at lower temperatures). Under these same conditions, fires are also more difficult to extinguish. Consequently, the presence of flammable contaminants and debris (especially grease, oil, and carbon deposits) in industrial oxygen systems dramatically increases the risk of accidental oxygen fires. What’s more, a build-up of these kinds of contaminants can damage valves and reduce the functionality of emergency shut-off systems in oxygen service equipment, further increasing the risk of personnel injury, system and product damage, and production delays due to fires and/or explosions.
What Is Oxygen Cleaning?
Oxygen system cleaning (or “oxygen cleaning”) involves using different techniques, equipment, and solvents to remove contaminants from oxygen service equipment. Oxygen cleaning techniques are unique because they use oxygen-compatible solvents and specially-designed equipment and processes to ensure the safe and complete removal of hazardous and potentially fire-causing contaminants.
Several different governing bodies regulate the solvents, equipment, and processes used in oxygen cleaning, as well as the standards for industrial oxygen system cleanliness in different sub-sectors. This includes the Compressed Gas Association (CGA), the Institute of Environmental Services and Technology (IEST), ASTM International (formerly the American Society for Testing and Materials), SAE International (the Society of Automotive Engineers), and NASA’s Kennedy Space Center (KSC). While the overarching philosophies of these organizations have always largely agreed with each other, their specific requirements and recommendations have been historically inconsistent. Recent revisions to many key regulations have aimed to create a more uniform standard for oxygen service cleaning and the overall maintenance of industrial oxygen systems. As these revisions take effect and every in-house and third-party oxygen cleaning provider adjusts their services to comply, these revisions will have significant operational and financial consequences for industrial companies and their oxygen systems.
What Are Current Oxygen Cleaning Standards & Revisions?
Significant recent revisions to oxygen cleaning regulations establish equivalent standards and requirements so that protocols agree within and across sub-sectors (and, notably, within and across geographic/governing borders). This also includes establishing deferments between standards so oxygen cleaning technicians can follow the most relevant/up-to-date recommendations and requirements. The current literature for oxygen cleaning practices and cleanliness of equipment used in oxygen service includes:
- CGA 4.1 - 2018 revisions to CGA guidelines create “internationally harmonized” standards that apply across sub-sectors and to an immense number of different pieces of equipment used in oxygen service. Qualified oxygen cleaning technicians can modify and apply these standards and practices to auxiliary parts of industrial oxygen systems (and other oxidizer systems, like nitrous oxide) that are not explicitly discussed by current regulatory literature.
Arguably the most detailed set of standards and recommendations for oxygen cleaning services, this revised edition includes detailed protocols for every stage of the cleaning process for equipment used in oxygen service. These protocols range from planning/scheduling oxygen cleaning services, specific pre-cleaning, cleaning, and drying procedures, and post-cleaning inspections. Moreover, because these revisions resulted from international collaboration, its recommendations are applicable for and intended for use in industrial oxygen systems in the US, Asia, Europe, and Japan.
- IEST-STD-CC1246 - The publication of IEST-STD-CC1246D in 2002 caused significant changes to oxygen cleaning regulations and recommendations for industrial oxygen systems, as it facilitated the application of measurement standards previously solely used for military purposes to a vast number of non-military oxygen systems. Revision-D changes also defined cleanliness levels for oxygen service equipment and systems that included liquids and components.
With its publication in 2013, The most significant revision-E changes to surface cleanliness standards for equipment involved in oxygen service are the creation of mutually-agreed-upon alternative cleanliness level designations to accommodate sub-sector-specific applications of oxygen service equipment. Additional revisions involve (1) rounding the maximum allowable number of particles of each particle size bin; (2) the creation of an explicit “particle fallout” standard which allows for and constrains acceptable levels for the accumulation of additional particle contaminants via fallout following the initial surface cleanliness determination; and (3) the additional creation of categorical “visible cleanliness” standards for aerospace equipment based on light intensity and viewing distance.
- ASTM G93 - This detailed guide is designed specifically for use by qualified oxygen cleaning technicians to aid in the selection of the best available methods, solvents, and equipment for use in unique industrial oxygen systems. This international standard, unlike other guides, includes and proposes a series of nonmandatory, yet practical ranges of surface cleanliness measurements under general operating conditions of industrial oxygen systems. Notably, these protocols defer to/cite both CGA and SAE recommendations and requirements. Nevertheless, this series of recommendations and protocols is admittedly insufficient for use in sub-sectors that require precise levels of cleanliness and/or which would result in above-average levels of contamination. It also does not propose specific surface cleanliness measurement standards.
- SAE ARP1176/A - ARP1176/A detail SAE recommendations for oxygen cleaning protocols and surface cleanliness standards in aerospace-specific applications. Initially published in 2009, “SAE ARP1176” designated cleanliness expectations that were “strongly dependent” on the capabilities of involved oxygen cleaning technicians. In 2013, these recommendations were stripped of their protocols for packaging and transportation of aircraft oxygen service equipment (now described separately in SAE AIR5742). The latest revisions, published in 2018 and titled “SAE ARP1176A,” ensure that surface cleanliness standards and enforcement are now applicable to metallic and non-metallic parts in industrial oxygen systems and rely on a new“cleanliness coding scheme” that quantifies and unifies expectations for compliance.
- KSC-C-123 - Used by NASA to designate acceptable “surface cleanliness” of aerospace hardware. Though KSC-C-123 has not been formally updated since July 2009, it deferred first to IEST-STD-CC-1246D for establishing acceptable levels of particle and nonvolatile residue contamination remaining after any oxygen cleaning process. Consequently, the above-listed changes to IEST standards, as described in IEST-STD-CC-1246E, have resulted in the revision or redesignation of the maximum allowable number of particles of certain sizes.
How Do New & Revised Recommendations/Regulations Impact Industrial Businesses?
The above-listed revisions to the most-trusted sources of information about oxygen cleaning standards contribute to four distinct trends in industrial oxygen system cleaning expectations and compliance:
- The unification of oxygen cleaning standards across both sub-sectors and borders;
- The expansion of regulations to include industrial oxygen systems operating under different pressures, with different oxygen concentrations, and even using different oxidizers;
- The extension of cleanliness protocols to account for the auxiliary parts of oxygen systems (rather than just the equipment most-directly used for oxygen service);
- The establishment of clear deferrals and referrals across different standards.
Together, these trends are changing how oxygen cleaning providers do business and how businesses can (and are required to) maintain industrial oxygen systems. For example, businesses that operate multiple internationally-located plants or cross-border pipelines have much clearer instructions for consistently maintaining all facilities and oxygen service equipment. Consequently, businesses should find that the push toward unified, streamlined recommendations, requirements, and protocols for oxygen cleaning makes the process of maintaining industrial oxygen systems easier and safer. What’s more, following clearer, more consistent standards and protocols should reduce much of the risk associated with working with oxygen service equipment as well as the number of accidental fires, the frequency of personnel and product damage, and the amount of time spent taking oxygen systems offline for repair.
That said, these benefits are dependent on working with qualified oxygen cleaning providers who understand and stay up-to-date with cleaning recommendations and processes as well as surface cleanliness measurement practices. Here at Precision Fabrication and Cleaning, we take pride in the fact that our oxygen cleaning services are not only functionally fast, safe, and effective, but are also well-informed and supported by the standards established by the most recent research. All our precision cleaning services for industrial oxygen systems are [specific organization] compliant, and all our oxygen cleaning technicians are highly qualified, certified, and continually trained in the best practices of the industry. Contact us today to find out more.