Oxygen Cleaning
Oxygen Cleaning Services
Oxygen cleaning, also known as, cleaning for oxygen service (CFOS) is a specialized process for removing contaminants from components and systems used with gaseous or liquid oxygen (GOX, LOX). It is critical for safety, as it reduces the risk of fires, explosions, and autoignition in oxygen-enriched environments.
The main contaminants removed are:
Organic Compounds
Volatile organic compounds (VOCs), hydrocarbon-based greases and oils
Inorganic Compounds
Nitrates, phosphates, water-based detergents, cutting oils, mineral acids
Particulates
Weld slag, metal filings, dust, lint, fibers
The primary concern involves the following contaminants, which can pose serious hazards in oxygen systems:
Hydrocarbon residues
Hydrocarbon residues can ignite at unexpectedly low temperatures in oxygen-rich atmospheres, potentially causing fires or explosions.
Metallic particles
Metallic particles traveling at high velocities in oxygen streams can create sparks or hot spots upon impact, potentially igniting contaminants or system components.
Proper oxygen cleaning is essential for all equipment and components before use in oxygen service. This includes removing even small amounts of manufacturing residues like oils and greases. Thorough cleaning helps prevent component malfunction, ensures product purity, and most importantly, eliminates combustion hazards in oxygen-enriched systems where fires can spread rapidly and explosively.
ON-SITE
Whether you’re conducting a planned shutdown or require emergency response, Astro Pak can mobilize crews from one of our nationwide locations to your facility, utilizing a modern fleet of service vehicles, pump skids, and our chemistries and processes. We provide passivation, surface finish, and a wide range of chemical cleaning services, circulating our chemistry through your systems and equipment.
SHOP
For components, parts and sub-systems that can be cleaned out-of-place, our shops are well suited to meet your cleaning and passivation requirements. Our nationwide shop facilities deliver prompt and reliable service and features state-of-the-art equipment that can accommodate hardware of all sizes and volumes. We have dip tanks up to 40ft and overhead bridge cranes with 10 ton lifting capacity for oversized parts.
Cleanroom
For cleanliness critical components, Astro Pak offers coast-to-coast Cleanroom Services facilities, featuring ISO 14644-1 certified Class 5, 6, and 7 cleanrooms and labs of various sizes and capabilities. These highly controlled environments support processes such as ultrasonic cleaning, pressure and cold shock testing, clean assembly, vacuum-sealed packaging, and cleanliness verification for particle count, TFS, and NVR.
Why Choose Astro Pak?
Astro Pak oxygen cleaning services adhere to internationally recognized published standards such as CGA G-4.1, Cleaning of Equipment for Oxygen Service. This standard describes the cleaning methods and requirements for equipment used in the production, storage, distribution, and use of liquid and gaseous oxygen to reduce the risk of fire, explosion, or promotion of combustion. Cleaning in accordance with this publication is required for all surfaces in contact with a gas or liquid that has an oxygen concentration greater than 23.5%.
Did you know?
Astro Pak Downey, CA cleanroom was featured in the CGA Handbook for cleaning components, equipment, and systems for oxygen service
Note: Data for assessing the compatibility of non-metallics (i.e., organics) with gaseous oxygen (GOX) and liquid oxygen (LOX) can be found in the ASTM G63 Standard, Guide for Evaluating Nonmetallic Materials for Oxygen Service.
Markets Served
Aerospace & Space
We offer a wide range of process methods ranging from hand detail cleaning, high pressure spraying, ultrasonic, and flow through circulation among others.
Chemical Manufacturing & Distribution
Passivation, oxygen cleaning, and surface maintenance services for high-purity water systems, liquid gas tanks, and distribution equipment, ensuring contaminant-free operations.
Water Wastewater
Our comprehensive range of pre-commissioning (or pre-operational) services include organic contamination and mill-scale removal, sanitization, disinfection, and passivation of piping and equipment.
Related Services
Precision Cleaning
Highly controlled environments supporting processes such as ultrasonic cleaning, pressure and cold shock testing, clean assembly, vacuum-sealed packaging, and cleanliness verification for particle count, TFS, and NVR.
Cleanliness Verification Testing
A critical step in the precision cleaning process is cleanliness verification testing, which ensures that cleaned parts and components meet the determined cleanliness level as noted in the specification.
Passivation
Passivation chemically treats stainless steel to remove contaminants and form a protective layer, enhancing corrosion resistance. Our Ultra Pass® process uses a citric acid blend for superior results, ensuring equipment longevity.
Frequently Asked Questions
Astro Pak adheres to internationally recognized standards such as CGA G-4.1, which outlines the cleaning methods and requirements for equipment used in oxygen service to reduce the risk of fire or explosion.
The main contaminants removed during oxygen cleaning include organic compounds (VOCs, hydrocarbon-based greases and oils), inorganic compounds (nitrates, phosphates, water-based detergents), particulates (weld slag, metal filings, dust), hydrocarbon residues, and metallic particles.
After oxygen cleaning, Astro Pak conducts cleanliness verification testing, which may include methods like particle counting, TFS, and NVR, to ensure that the components meet the required cleanliness levels as specified by the standards.
Oxygen Cleaning is a subset of Precision Cleaning and specifically targets the removal of contaminants that can pose hazards in oxygen-enriched environments, such as hydrocarbons and metallic particles.
Oxygen Cleaning, also referred to as Cleaning for Oxygen Service (CFOS), is cleaning parts that will be used in an oxygen or oxidizer enriched environment. To accomplish this, parts are not cleaned using oxygen; rather, the parts are degreased using solvents and/or alkaline detergents in an aqueous solution to remove the contaminants and residue that are not compatible with an oxygen system. This cleaning process is important to ensure that substances which are incompatible with oxygen or other oxidizers are removed from the part. Failure to do so may result in system failure, product failure, and/or combustion.
There is a wide range of cleanliness criteria for oxygen service depending on the use of the system. The less critical conditions include breathing air, non-oxygen gases; and the more critical conditions include liquid oxygen, high pressure gaseous oxygen, spacecraft systems, etc.
For each environment there is a set cleanliness criteria established. Usually the standard is noted in a cleaning specification, and the cleanliness verification target ranges from 47 mg/sq foot of non-volatile residue (NVR) for the least critical conditions, to 1 mg/sq foot of NVR and below for the more critical systems. Cleanliness criteria can be less than 1 mg/sq foot for oxygen systems, but typically 1 mg/sq foot of NVR represents the more common lower limit range of the requirement.
After a part has been cleaned and verified, it is important to package the part correctly in order to maintain the cleanliness level until use or assembly into the final hardware, equipment, or system. For high pressure and liquid systems, cleanliness criteria usually also includes particle count limits. The allowable particles are typically in the range of level 100 – 300 (measured in micrometers), as noted in such specifications as IEST 1246.
Failure to properly clean components can result in combustion hazards in oxygen-enriched systems, leading to fires, explosions, or component malfunctions due to the presence of contaminants like hydrocarbon residues and metallic particles.
Yes, Astro Pak has the capability to clean large and complex systems, whether on-site, or at one of our locations. We utilize specialized equipment that can accommodate a wide range of sizes and complexities, ensuring thorough cleaning of all components.
Astro Pak’s oxygen cleaning process typically involves an initial assessment of the contamination, followed by the application of appropriate cleaning agents and techniques to remove organic and inorganic compounds, particulates, and other contaminants. The process typically concludes with thorough rinsing, drying, and verification testing to ensure compliance with customer specifications.