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Divers Check Your Tanks: DOT Urgently Searching For Invalid Hydro Tests
Smithsgold - 9/22/2015 12:39 PM
Category: Health & Safety
Replies: 1

Divers Check Your Tanks: DOT Urgently Searching For Invalid Hydro Tests

The US Department of Transportation (DOT) Pipeline and Hazardous Materials Safety Administration is asking for immediate assistance from divers to identify scuba tanks which may have an invalid RIN number (Retesters Identification Number). This number is used to identify hydrostatic testing facilities and appears stamped into the tank, near the neck, whenever a hydrostatic test is performed. Scuba tanks require this test every 5 years.

An image of the invalid RIN appears as a letter “C” over the letter “L”, stamped between the month and year of the hydro test date:

The Department is attempting to locate the place where cylinders bearing this marking were tested, and asking anyone who is in possession of a cylinder with this improper RIN (or knows where one is) to contact them immediately. If you find a tank with this marking, please immediately contact Earl Whitley at or 909-222-9546.

One tank with such markings has already been located in Hawaii and another is known to be in California.

If you are in possession of this cylinder or one without a proper requalification marking, please ensure that it is tested before being placed into service.

Further information regarding cylinders can be found at