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Technical Support Document

Crown Markings of a Medical Oxygen Cylinder

February 22, 2002

The Department of Transportation (DOT) and Transport Canada (TC) require that a cylinder made in compliance with their specifications be marked on the crown with certain information. Over the years the format used by Catalina Cylinders and Cliff Impact Division of Catalina Cylinders to display these markings has changed a few times. Shown below is the crown marking diagrams currently being stamped on the standard medical "E" cylinders (24 cu ft 2015 psi) manufactured by Catalina Cylinders (Garden Grove, California) and Cliff Impact Division of Catalina Cylinders (Hampton, Virginia). The crown markings noted below are in the sequence as stamped on the cylinder crown but, for your convenience, are displayed in a straight line format so you do not need to rotate this document to read the markings. Under the diagrams is a list of each of the specific crown markings followed by a brief explanation of that marking. The information provided by the markings is the same, regardless of the different stamping formats used by Catalina Cylinders and Cliff Impact Division of Catalina Cylinders over the years.

Crown Marking Diagram
Catalina Cylinders (Garden Grove, California)
                        Medical "E" Cylinder                        
DOT-3AL2015..MMXXXXXXX M4002 01*02 CATALINA M24 Oxygen Symbol TC-3ALM139

Marking Explanation of Marking
DOT-3AL The U.S. regulatory authority, the Department of Transportation "DOT", and specification "3AL" to which the cylinder is manufactured in compliance.
2015 The service pressure "2015", in pounds per square inch (psi), of the cylinder.
MMXXXXXXX The cylinder serial number. The serial number prefix of "MM" is specific to the 24 cuft 2015 psi medical oxygen cylinder, manufactured at Catalina Cylinders, Garden Grove, California facility, followed by "XXXXXXX" a seven-digit number.
M4002 The DOT Manufacturers Number (M-Number) "M4002" issued to Catalina Cylinders, Garden Grove, California facility.
01*02 The original hydrostatic test date of the cylinder, month "01", separated by "*" the Independent Inspection Agency (IIA) symbol, followed by the year "02", performed at the time of manufacture of the cylinder. The "*" represents the symbol of the Independent Inspection Agency (IIA) performing the inspection of and certifying the acceptance of the cylinder at the time of manufacture.
CATALINA The name of the manufacturer of the cylinder.
M24 The cylinder identifier. Identifies the cylinder is designed for medical service "M" with a capacity of 24 cu ft "24" of oxygen, hence M24.
Oxygen Symbol Actually an "O" with a "2" inside the "O". This signifies that the cylinder is for oxygen service and the lot of cylinders was subjected to residual hydrocarbon testing.
TC-3ALM The Canadian regulatory authority, Transport Canada "TC" and specification "3ALM" to which the cylinder is manufactured in compliance.
139 The service pressure "139" (in bars) of the cylinder.


Crown Marking Diagram
Cliff Impact Division (Hampton, Virginia)
                        Medical "E" Cylinder                        

DOT-3AL 2015 AS XXXXXXX O2 CLIFFDIV 01*02 TC-3ALM139

Marking Explanation of Marking
DOT-3AL The U.S. regulatory authority, the Department of Transportation "DOT", and specification "3AL" to which the cylinder is manufactured in compliance.
2015 The service pressure "2015", in pounds per square inch (psi), of the cylinder.
AS XXXXXXX The cylinder serial number. The serial number prefix of "AS" is specific to the 24 cuft 2015 psi medical oxygen cylinder, manufactured at the Cliff Impact Division of Catalina Cylinders, Hampton, Virginia facility, followed by "XXXXXXX" a seven-digit number.
O2 The "O2" signifies that the cylinder is for oxygen service and the lot of cylinders was subjected to residual hydrocarbon testing.
CLIFFDIV The DOT recognized Manufacturer's Symbol "CLIFFDIV", an acceptable alternative to the DOT M-Number issued to Cliff Impact Division of Catalina Cylinders, Hampton, Virginia facility.
01*02 The original hydrostatic test date of the cylinder, month "01", separated by "*" the Independent Inspection Agency (IIA) symbol, followed by the year "02", performed at the time of manufacture of the cylinder. The "*" represents the symbol of the Independent Inspection Agency (IIA) performing the inspection of and certifying the acceptance of the cylinder at the time of manufacture.
TC-3ALM The Canadian regulatory authority, Transport Canada "TC" and specification "3ALM" to which the cylinder is manufactured in compliance.
139 The service pressure "139" (in bars) of the cylinder.


Catalina Cylinders - West
Corporate Headquarters
7300 Anaconda Avenue
Garden Grove, California 92841 USA
Phone: (714) 890-0999
Fax: (714) 890-1744
Email Us!

Catalina Cylinders - East
Cliff Impact Division
2400 Aluminum Avenue
Hampton, Virginia 23661 USA
Phone: (757) 896-9100
Fax: (757) 896-9143
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