How to Read a Scuba Tank


Familiarization with equipment and establishing a regular maintenance routine are habits that ensure a diver's safety. The scuba or air tank is no exception, and each scuba tank should be visually inspected every two years and complete hydrostatic testing every five to ensure the interior and exterior of the tank are sound enough to support pressurized air. The crown markings are imprinted information that enable manufacturers to track each unit in case of problems. When buying a used scuba tank, these crown markings provide information on the quality and care of the tank.

Things You'll Need

  • Table
  • Ankle weights (2)
  • Scuba tank
  • Pen
  • Paper
  • Flashlight (optional)
  • Place the scuba tank on the table and orient it so that the tank valve is pointing to you. Place ankle weights on each side of the scuba tank to secure its position.

  • Identify three rows of imprinted letters at the top (crown) of the tank, near the tank valve. Write down each row of letters and numbers.

  • Translate the first row of information using the legend below and reading each line from left to right:
    Transport mark: "TC" or "CTC" means "Transport Canada"
    Tank material: "3AL" means the tank is aluminum
    Working pressure in bar (e.g., M207)
    Tare weight in kilograms (e.g., T11.3KG)

  • Translate the markings in the middle row:
    "DOT" specifies US Department of Transportation
    Tank material code (e.g., "3AL" is the code in the US)
    Working pressure in PSI (e.g., 3000)
    Tank model (e.g., S80)
    Manufacturer name or code (e.g., LUXFER or M4002)
    Tank serial number assigned (e.g., U123456)

  • Translate the markings on the bottom line:
    Month and year of hydrostatic test, each expressed in two digits and separated by an inspection code (e.g., 01A00 for January 2000 independently inspected)
    Carbon dioxide capacity (e.g., 20#CO2)
    Tare weight in pounds (TW24.9)

  • Check whether additional markings are included such as:
    Overfill is indicated with a "+" sign which enables some steel tanks to be filled 10% greater than the pressure indicated on the tank (see Step 3 or Step 4)
    Test pressure in PSI (e.g., TP4500 which is greater than the working pressure)

Tips & Warnings

  • Note the hydrostatic date (in Step 5) and see whether the date is within the last five years. If the date of hydrostatic testing is more than five years ago, the tank needs to undergo hydrostatic testing before use.

Related Searches


Promoted By Zergnet



You May Also Like

  • When to Hydro Test SCUBA Tanks

    Scuba tanks and all pressurized cylinders must be regularly checked to ensure the cylinder can safely be used and not explode or...

  • How to Test Co2 Cylinders

    High pressure cylinders for storing carbon dioxide (CO2) gas or a mix of gases are used for a variety of purposes, including...

  • How to Check the Dates on Your CO2 Tanks

    Pin valve CO2 tanks are widely used to power paintball guns. These tanks are rated by the volume of liquid CO2 the...

  • DOT Requirements for Air Cylinders

    Cylinders that carry pressurized air are classified as hazardous by the Department of Transportation and shipping regulations for air cylinders are listed...

Related Searches

Check It Out

10 Delicious Game Day Eats That Rival the Game

Is DIY in your DNA? Become part of our maker community.
Submit Your Work!