Compressed Gas Cylinder Identification -

Cylinder Identification
Cylinder Markings
Printer-Friendly Page

Also see Cylinder Comparisons for charts and diagrams of cylinder sizes.

Cylinder Identification and Marketings Packaging and Color
Airgas uses a teal paint to identify specialty gas cylinders. Here are the highlights of our cylinder packaging:
• A cylinder neck ring is permanently fixed below the base of the valve. Airgas does not use color coding to identify cylinder contents. Cylinder color should never be used to identify contents. Please read the contents label.
• A shoulder label indicates the product’s shipping name and identification number. On pure products, a grade label is also applied to the cylinder shoulder. The shoulder label identifies cylinder contents.
Airgas specialty gas cylinders are stamped with markings designed to indicate ownership, specifications, pressure ratings, and other important data. Airgas also utilizes a bar code label for product identification and tracking.

1. Cylinder Specification:
• DOT—Department of Transportation (previously ICC – Interstate Commerce Commission), which is the regulatory body that governs the use of cylinders.
• Specification of the cylinder type of material of construction (e.g., 3AA).
• Service or working pressure in pounds per square inch (e.g., 2,265 psig).

2. Cylinder Serial Number

3. Date of Manufacture:
• This date (month-year) also indicates the original hydrostatic test.

4. Neck Ring Identification:
• The cylinder neck ring displays the name of the original owner of the cylinder.

5. Retest Markings:
• The format for a retest marking is: Month – Facility – Year – Plus Rating – Star Stamp. • The + symbol (Plus Rating) indicates that the cylinder qualifies for 10% overfill. • The H symbol (Star Stamp) indicates that the cylinder meets the requirements for 10-year retest, instead of a 5-year retest.
6. Bar Code Label:
• The bar code label provides a unique cylinder identifier and is used by computer systems to track cylinders throughout the fill process. As an optional service, we have the capability of tracking cylinders to and from customers.

7. Cylinder Manufacturer’s Inspection Marking

8. Cylinder Tare (Empty) Weight:
• This value may be preceded by the letters TW.

D.O.T. Classifications
Your compressed gas cylinders will have one or more of the hazardous materials placards shown at right. The United States Department of Transportation (US DOT) in Title 49 Section 173 of the United States Code of Federal Regulations (49 CFR 173) requires the use of hazardous materials placards when shipping compressed gases. These hazardous materials placards are indended to indicate the general hazards associated with the contents of the gas in the cylinder. For complete hazardous material information, refer to the Material Data Safety Sheet (MSDS).