Aluminum cylinders should not be exposed to elevated temperatures, 350°F (176°C) or greater, or the action of fire for any period of time. In section (f) (4) of 49 CFR part 173.34, DOT-3AL and DOT-4E, aluminum cylinders subjected to fire must be removed from service. In CGA pamphlet C-6.1; Standards For Visual Inspection of High Pressure Aluminum Gas Cylinders, it states that cylinders heated to metal temperatures in excess of 350°F (176°C) must be condemned.
The CGA recognizes the effects of high temperature on aluminum cylinders and issued a safety bulletin SB-22; Aluminum Cylinders – Guidelines for a Heat Exposure Indicating System. In this safety bulletin the use of heat indicating devices on aluminum cylinders is only a recommended practice and is not a requirement by the CGA or any DOT specification. However, in some applications, Catalina Cylinders believes the use of such devices makes sense. CGA’s safety bulletin SB-22 identifies many applicable parameters of a heat indicating system but does not identify sources of these systems.
Following are a few sources of different types of heat (temperature) indicating systems.
American Thermal Instruments, Inc.
Phone: 800 648-6339
Fax: 937 252-6509
Omega Engineering Incorporated
The Temperature Handbook
Temperature indicating labels, Crayons, cements, and paints
Phone: 203 359-1660
Fax: 800 848-4271
Temperature indicating labels, Crayons, and pellets
Phone: 562 692-5911
Fax: 562 695-2323
Temperature indicating devices
Phone: 714 879-2901
Fax: 714 870-8136
Catalina Cylinders recommends that when choosing a heat indicating device, make sure you select a non-reversible temperature indicating device and that the device is compatible with the environment in which the cylinder will be used.