Which term describes the pressure of a gas inside a full receptacle, at a standard temperature, used for labeling?

• A. Working Pressure
• B. Atmospheric Pressure
• C. Gauge Pressure
• D. Absolute Pressure

Answer: (A)

The main idea here is how compressed gas cylinders are labeled with a safe, standardized pressure value. The pressure used for labeling is the maximum pressure the cylinder is designed to hold when it is full, measured at a reference (standard) temperature. This is the working pressure, also called service pressure. It reflects the capacity of the cylinder to deliver gas safely and guides what equipment (valves, regulators, piping) must be able to withstand.

This choice makes the most sense because it directly communicates the cylinder’s rated fill pressure for safe operation. Temperature affects the actual pressure inside a gas-filled bottle, but the label uses the standard temperature reference so the rating is consistent and comparable across cylinders.

The other terms describe different pressures: atmospheric pressure is the surrounding air pressure, which isn’t the internal cylinder pressure; gauge pressure is the pressure above atmospheric pressure (what a gauge would read); absolute pressure is the total pressure relative to a perfect vacuum, which isn’t how cylinder contents are described for labeling.