Which statement about 4B195 is correct?

• A. 195 psi is the normal pressure and can be tested hydrostatically up to 585 psi
• B. 195 psi is the maximum allowable pressure
• C. 195 psi is the model number
• D. 195 psi is unrelated to pressure

Answer: (A)

The main idea here is understanding that a cylinder has a designated operating (working) pressure and a separate, higher hydrostatic test pressure used to verify the shell’s safety and integrity. For this model, the value you use for normal operation is the pressure it’s designed to handle in regular use, while the hydrostatic test pushes the vessel to a much higher pressure to reveal any hidden flaws in the material, welds, or joints.

So, saying that the normal pressure is the working pressure and that the vessel can be tested hydrostatically up to a higher limit captures how these two pressures function together. The hydrostatic test isn’t about operating conditions; it’s a safety check that the cylinder can withstand more extreme pressure without failing. The other interpretations would mislabel what those numbers represent, such as treating the value as a simple maximum at all times, as a model identifier, or as something unrelated to pressure.