The need for oxygen cleaning stems from the fact that there are environments, usually artificial, that contain highly oxidizing atmospheres. An example of such an atmosphere is a spacecraft that is filled with pure oxygen. Another example is a pipeline that transports pure oxygen under high pressure. Other strong oxidizers besides oxygen also exist, such as hydrogen peroxide in concentrated form. The thing that is common between all of them, and the reason for oxygen cleaning, is that all of the highly oxidizing atmospheres and substances can react with contaminants on hardware, sometimes causing a fire or even an explosion.
The first type of contaminant of concern is a hydrocarbon-based residue. These are often made up of small amounts of oils and greases, which are commonly used in manufacturing environments and end up on the surfaces of newly-produced hardware. When a hydrocarbon-based residue comes into contact with an enriched oxygen atmosphere or a strong oxidizer, the temperature at which it will ignite and burn is lowered – sometimes low enough so that it will catch fire at room temperature or even below! And if a fire starts, the presence of so many oxygen molecules in the immediate area means that it will burn hotter and faster than usual. If it burns fast enough, it may even cause an explosion.
The other contaminant of concern is particulate matter. These can travel in a stream of moving gas within a pipe or tube. In an oxygen-enriched atmosphere, especially one under high pressure, things that normally are not considered flammable may indeed catch fire and burn. All they need is a spark! This is where the particles come in. If they are traveling with the gas stream, and they strike the wall of the pipe or tube with enough velocity, a small hot spot may develop. If the particle is metallic, a spark might even be created. In either case, contaminants in the pipe, or even the wall of the pipe itself, may catch fire. If that happens, the pipe may rupture and high-pressure gas escapes, endangering everything in the area. High-pressure gas ruptures are essentially explosions, and shrapnel being propelled for some distance is common.
The oxygen cleaning process involves two special steps: cleaning the surface using an approved cleaner and process, and then verifying that the surface is clean enough to safely be used in its intended environment. A variety of cleaning processes may be used: aqueous detergents, solvents, ultrasonic cleaning, high-pressure spray cleaning and other methods are all common. The cleaned material is handled with gloves in a clean room so that re-contamination does not occur. At Astro Pak, the material is then tested and certified for use by our Verification Laboratory. Our degreed Chemists test the critical surfaces for residues using a process called Gravimetric Non-Volatile Residue Mass Determination, usually abbreviated as simply NVR testing. They also count and size any remaining particles found on the critical surfaces. In this way, they assure the absence of any material that could become flammable, or come loose in a gas stream and strike the wall of a transport pipeline, thus verifying that the material is safe for use in a highly oxidizing environment.
What is the difference between Oxygen Cleaning and Precision Cleaning?
Both require that a surface be cleaned, but Precision Cleaning requires some sort of measurement or analysis of the surface cleanliness to quantify and/or validate the level of cleanliness achieved.
Trust the Experts
Astro Pak has nearly 60 years of experience in precision cleaning for oxygen service as a supplier to high-tech industries. We are able meet the requirements of literally hundreds of industry specifications. This includes aerospace contractors, ULA, NASA, the Department of Defense, and many private industries and organizations. We have experience with large high-pressure gaseous oxygen as well as liquid oxygen tanks, lines, tubing and valves. We have worked on many ozone systems, both large and small.
Our facilities are large, modern, and state of the art. Our most notable location in our California ISO 9001/AS9100 Certified Class 5 (class 100) and Class 6 (Class 1000) cleanrooms. However, we also offer this service in our newest location in Florida, called Chemko. We also offer a fleet of mobile cleanrooms, equipment and chemicals to your site.
Hardware that enters our cleanroom includes a real-time electronic tracker to keep customers better informed on the status of order. Not only do we clean and package, but we also assemble items ranging in size from small fasteners to huge vessels. Our Research & Development department can develop a precision cleaning process that meets any requirement. Our in-house laboratories are dedicated to finding solutions so that customer requirements can be met in an efficient and cost-effective manner.
Astro Pak commits to providing customers with the level of excellence they expect and deserve by:
- Advanced Chemistry & Process Technology
- Highly Trained Personnel delivering superior consulting services
- Rapid Response
- State of the Art Equipment and Locations Nationwide
- Superior Documentation (Meeting cGMP Requirements)
In addition, our Certification packages are QMS/cGMP compliant for your systems and equipment maintenance records. Let our experienced and credentialed team of chemists, engineers, and other professionals on staff EXCEED your expectations. Contact us today for more information.
We Can Meet Your Cleaning Standards
Astro Pak Corporation is capable of performing clean assembly to the specifications requirements. Whether its valves, regulators, gas and fluid transfer panels or tubing / piping systems, we can do it all! Some of the specifications that we routinely meet include:
- CGA 4.1
- IEST-STD-CC-1246 revisions D & E
- Praxair GS-38
- ASTM G93
- ANSI B 40
- SAE 1176
- SAE ARP 1176
We also will meet Individual Private Industry and Government Specifications – call us for information!