The Department of Transportation (DOT) and Transport Canada (TC) require that cylinders made in compliance to their specifications be marked on the crown with certain information. Over the years the format used by Catalina Cylinders and Catalina East Division to display these markings has changed a few times. Shown below is an example of the current crown marking stamped on the standard 20 # CO2 cylinders manufactured at Catalina Cylinders, Garden Grove, CA. Under the example of the crown marking is a list of each of the specific crown markings, followed by a brief explanation of that marking. The descriptions of the markings are the same regardless of the different stamping formats used over the years .
Example of crown markings on a 20 # CO2 Cylinder:
DOT-3AL1800FXXXXXXX M4002 07C08 B20 U18 T25.2LB TC-3ALM124 T11.5KG CATALINA
| Marking |  |
Description |
| DOT-3AL | |
The U.S. regulatory authority, the Department of Transportation (DOT), and specification, 3AL, to which the cylinder is manufactured in compliance(required mark). |
| 1800 | |
The service pressure, in pounds per square inch (psi), of the cylinder (required mark). |
| FXXXXXXX | |
The serial number of the cylinder. For Catalina Cylinders, the serial number prefix of “F” is specific to the 20# CO2 cylinders followed by a seven digit number. |
| M4002 | |
The M-number or Manufacturers Number issued by the DOT to the manufacturer, Catalina Cylinders. |
| 07C08 | |
The original hydrostatic test date of the cylinder, month followed by year, performed at the time of manufacture of the cylinder. The C 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 (required mark). |
| B20 | |
The cylinder identifier (product name). It identifies the market, “B” for beverage, and capacity “20” for a capacity of 20# of CO2 charge, of the cylinder. |
| U18 | |
The cylinder outlet thread designation as specified in CGA TB-16. |
| T25.2LB or TW25.0LBS | |
The tare weight (in lbs.) of the empty cylinder package. The empty cylinder package includes the cylinder, the valve, the carrying handle and the snap ring (required mark). |
| TC-3ALM | |
The Canadian regulatory authority, Transport Canada (TC), and specification, 3ALM, to which the cylinder is manufactured in compliance (required mark). |
| 124 | |
The service pressure of the cylinder expressed in metric units, bars (required mark). |
| CATALINA | |
The name of the manufacturer of the cylinder. |
| T11.5KG | |
The metric tare weight (in kgs) of the empty cylinder package. The empty cylinder package includes the cylinder, the valve, the carrying handle and the snap ring. |