Oxygen Cleaning
Introduction to Oxygen Cleaning:
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Because most materials, including metals, will burn in an oxygen-enriched environment, hazards are always present when using oxygen. Most materials will ignite at lower temperatures in an oxygen-enriched environment than in air, and once ignited, combustion rates are greater in the oxygen-enriched environment. Many metals burn violently in an oxygen-enriched environment when ignited. Lubricants, tapes, gaskets, fuels, and solvents can increase the possibility of ignition in oxygen systems. However, these hazards do not preclude the use of oxygen. Oxygen may be safely used if not all the materials in a system are flammable in the end-use environment or if ignition sources are identified and controlled. These ignition and combustion hazards necessitate a proper oxygen hazards analysis before introducing a material or component into oxygen service.
Oxygen cleaning: Copper, Stainless, Brass, Monel, & Carbon Steel.
Carolina Piping Services, Inc. cleans parts that are commonly used in the distribution, storage and production of gaseous Oxygen. The most commonly used specification in the industry for this type of cleaning are: CGAG-4.1
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NFPA 99C
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Praxair – GS-38 (Carolina Piping Services is a Certified Oxygen Cleaning Vendor for Praxair)
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ASTM B-819
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ASTM G93
Oxygen Cleaning
High Risk Components:
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Many of the typical components found in oxygen systems are particularly susceptible to one or more of the 10 possible ignition mechanisms. The following is a list of some of these components and the associated ignition mechanisms.
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Ball Valve: Particulate generation (particle impact) and quick-opening (adiabatic compression)
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Relief Valve: Chattering (mechanical impact or frictional heating)
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Globe Valve: Impingement even when fully open (particle impact)
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Butterfly Valve: Impingement even when fully open (particle impact)
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Flex Hose: Susceptible to adiabatic compression when dead-ended
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Regulator: Mechanical impact and high velocities generated (particle impact)
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Check valve: Chattering (mechanical impact/frictional heating)
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Filter: Pneumatic impact of contaminants on the filter element and possible particle impact if poorly located within the system
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Fittings: Particulate introduced into the system during assembly (particle impact)
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Soft goods: Impingement on polymers in gas stream (pneumatic impact, mechanical impact, and particle impact.
References: Oxygen Cleaning Standards
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PRAXAIR STANDARD GS.38: CLASS 2 CLEANING
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CGA G-4: Oxygen.
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CGA G-4.1: Cleaning Equipment for Oxygen Service.
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CGA G-4.3: Commodity Specification for Oxygen.
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CGA G-4.4: Industrial Practices for Gaseous Oxygen Transmission and Distribution Piping Systems.
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CGA G-4.6: Oxygen Compressor Installation and Operation Guide.
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CGA. P-2.5: Transfilling of High Pressure Gaseous Oxygen to be used for Respiration.
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CGA P-14: Accident Prevention in Oxygen-Rich and Oxygen Deficient Atmospheres.
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CGA SB-7: Rupture of Oxygen Cylinders in The Diving Industry.
•HANDBOOK OF COMPRESSED GASES
References: FDA
• Compressed Medical Gases Guideline
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References: NPFA Publications
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NFPA 43C: Storage of Gaseous Oxidizing Materials.
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NFPA 50: Bulk Oxygen Systems at Consumer Sites.
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NFPA 53M: Fire Hazards in Oxygen-Enriched Atmospheres.
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NFPA 69: Explosion Prevention Systems.
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NFPA 99B: Hyperbaric Facilities
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LC-HAZ-91: Fire Protection Guide to Hazardous Materials