July 1997

Air Products has recently received several reports from our Hometown, Pennsylvania Specialty Gas facility that several fluorine / nitrogen trailers have been returned with corrosion on their outlet manifolds. By their observations, we suspect that there may have been a fluorine leak on one of the CGA fittings prompting the customer to disconnect all pigtail connections and teflon tape these CGA fittings to obtain a tight seal. The problem was further compounded by the use of ammonia solution for leak detection. This ammonia solution introduced water to the area where the leak occurred, prompting hydrogen fluoride to be produced, thus causing corrosion problems.

As part of our commitment to Responsible Care®, we are notifying all fluorine customers of this problem and will address these issues during our Safety Site inspection visits. In the future we are recommending that our customers call Air Products immediately if they are having problems with leaking pipe connections on our trailers. Should there be an immediate need to resolve this problem to the point where you the customer disconnects the CGA fitting from the manifold, these fittings should be cleaned with a wire brush so that a metal to metal contact maybe maintained within the CGA fitting. By using teflon tape on these fittings, the high pressure gas within the trailer will actually cause the tape to cold flow over a period of time and a second leak will occur.

When leaking checking any fluorine system, we are recommending that KI strips be used, or a 5% by weight KI/water solution can be made for this purpose. By placing some KI solution on a paper towel or when using the KI strips, these strips can be held approximately one inch above the suspect area. Should there be any fluorine in the air, a color change will be indicated. By using this method of detection, no water will be applied to the piping system, thus reducing the formation of corrosion.

Should there be any additional concerns or questions regarding this problem, please your local Air Products representative and we will address these issues.

Contact the Air Products Technical Information Center:
For technical data, product specifications, safety and environmental information, and applications assistance:

Call 1-800-752-1597 (U.S.)
Call 1-610-481-8565 (other locations)
Fax 1-610-481-8690
Email gigmrktg@airproducts.com
Monday–Friday, 8:00 a.m.–5:00 p.m. EST

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