Luxfer Gas Cylinders strongly recommends that you make the following information available to any and all persons who handle and/or fill high-pressure aluminum gas cylinders:
You are warned that failure to strictly follow these guidelines could result in overheating of the cylinder which could weaken the cylinder, causing it to fail under pressure, exposing bystanders to serious injury or even death and/or loss of property.
- Do not expose any aluminum cylinder to temperatures in excess of 265ºF (130ºC).
- If you know or suspect an aluminum cylinder has been exposed to elevated temperatures BETWEEN 265ºF (130ºC) and 350ºF (175ºC), it MUST be hydrostatically retested before being returned to service.
Common evidence of exposure to elevated temperatures above 265ºF (130ºC) includes:
- Charring or blistering of the paint or other protective coating
- Distortion of the cylinder
- Melting of fuse plugs
- Charring or burning of labels
- Increases in total or permanent expansion from hydrotesting
- Distortion of valve or carrying handles
- Any cylinder exposed to the direct action of fire MUST be removed from service as its mechanical properties are adversely affected by exposure to high temperatures (49 CFR 173.34) and it may fail under pressure.
- Any aluminum cylinder exposed or suspected of having been exposed to temperatures in excess of 350º F (175ºC) MUST be condemned (CGA C-6.1) and removed from service.
- If your cylinder has a heat-indicating clear coat, it must be condemned immediately if the coat changes to a brown color.
The properties of aluminum cylinders rapidly degrade or change when temperatures exceed 350ºF (175ºC). The longer the exposure the greater the degradation of the metal, which weakens and may later fail under pressure. The higher the temperature above 350ºF (175ºC), the faster and greater the degradation.
To avoid the risk of cylinder failure and risk to human life, Luxfer strongly recommends that cylinders should only be repainted using paints that cure and dry at room temperature. These paints may be water-based although some areas permit solvent paints (check with your local authorities). A clear coat, which also cures and dries at room temperature, may be applied over the new paint. Use only paints specifically recommended for use on aluminum surfaces.
- Do not use caustic paint strippers or corrosive cleaners to remove paint from aluminum cylinders. They will damage the cylinder and weaken the metal which could later cause a failure under pressure.
- Do not remove old paint by using blasting media that will or may remove metal from the cylinder.
If you have any questions regarding the above, contact Luxfer's Customer Service at (951) 684-5110. If you are a professional refinisher or repainter of aluminum cylinders, please contact Luxfer for a special technical bulletin on cylinder repainting.