We are a contract manufacturing company in the process of looking for a supplier in the Northeast that provides the service of cleaning aluminum and brass machine parts to a CGA spec, CGA G-4.1. We are not familiar with the process that is required and therefore are at a loss as to the type of service supplier to contact. Internet searches have not provided much info.
Can you direct me to a source of information for cleaning for oxygen service or a listing of appropriate suppliers? Any help would be appreciated. M.D.
As you mention, the important aspect of this process is cleaning for oxygen service. CGA stands for the Compressed Gas Association, which has a standard for cleanliness of parts that are intended for oxygen service. I would recommend first understanding the requirements of the process. I visited the CGA web site (www.cganet.com) and, although I did not get the entire standard ($57 for a download, $76 for a hard copy), I was able to view the Table of Contents for the G-4.1 standard.
It would indicate that there are several options available to the user of the specification. For example, it lists steam, caustic, acid, solvent, vapor degreasing and mechanical cleaning all as available methods. Additionally, the standard details the inspection method and quality procedures. Although you may have difficulty finding jobshops that specialize in cleaning to this standard in your area, it would likely be possible to develop one. You would first need to obtain a copy of this specification, understand the applicability and requirements for your product. Then contact some cleaning jobshops in your area that perform similar processes and would be willing to work with you to establish the necessary cleaning standards.
For the readers: Below is a follow up from my October 2003 column (www.pfonline.com/articles/clinics/1003cl_clean3.html), regarding treatment of magnesium in order to achieve a 1,000 hour salt spray requirement. The general answer I provided was either anodizing or possibly a combination epoxy e-coat followed by an acrylic powder topcoat. The following is more information that I wanted to pass on.