In a DOT-4BA240 specification cylinder, the '240' indicates the cylinder's ...

• A. service pressure
• B. volume capacity
• C. burst pressure
• D. maximum internal temperature

Answer: (A)

In DOT cylinder markings, the numeric suffix shows the service (working) pressure the cylinder is designed to handle in normal use. The 240 indicates 2,400 psi of service pressure. This is the pressure the cylinder is allowed to contain during regular operation. It’s not indicating how much gas the cylinder can hold (volume), nor its burst pressure (which must be higher than the service pressure for safety), nor a maximum internal temperature. So the digits after the designation specifically convey the working pressure rating to ensure safe filling and use.