Low-pressure tankers are designed to haul liquids at pressures not exceeding what PSI?

• A. Forty pounds per square inch
• B. Forty PSIG
• C. 40 pounds per square inch
• D. 40 psi maximum

Answer: (D)

Low-pressure tankers are built to operate at a relatively small, controlled pressure. The design limit for these tanks is 40 psi, meaning they’re not meant to be pressurized above that level. In practice, this pressure is gauge pressure (PSIG), the pressure above atmospheric, which is why you may see references to 40 PSIG. The best way to answer the question is “40 psi maximum,” because it directly states the limit in the requested unit and clarifies that this is the maximum allowable pressure. Other phrasings can be less precise or introduce the gauge-versus-absolute distinction unnecessarily, even though they point to the same numeric value.