What does hydrostatic testing of propane cylinders verify?

• A. The color coding of the cylinder
• B. The gas purity
• C. The structural integrity of the cylinder shell
• D. The weight before use

Answer: (C)

Hydrostatic testing checks the cylinder’s ability to hold pressure without leaking or rupturing. The cylinder is filled with water and pressurized to a level higher than normal service pressure. If there are thinning spots, corrosion, cracks, or other weaknesses in the shell, the test will reveal them as leaks or deformation. This confirms the structural integrity of the cylinder shell over its use life.

It’s not about color coding, gas purity, or the weight of the cylinder; those are separate checks or indicators and don’t assess the shell’s strength.