Crown Markings of a Standard CO2 Cylinder


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.


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