PADI Divemaster Certification Practice Exam

What does a hydrostatic test primarily assess in a dive cylinder?

1. Structural integrity

2. Weight capacity

3. Metal fatigue

4. Volume displacement

The correct answer is: Metal fatigue

A hydrostatic test primarily assesses the structural integrity of a dive cylinder by determining its ability to hold pressure without failure. During this test, the cylinder is filled with water and subjected to higher than normal pressures to evaluate its strength and safety. If there are any flaws, deformities, or weaknesses in the material, they are likely to be revealed during this process. While metal fatigue can be a concern for dive cylinders, the hydrostatic test specifically targets the cylinder's structural integrity rather than directly assessing fatigue. Metal fatigue typically requires other forms of assessment, such as visual inspections and magnetic particle testing, rather than a hydrostatic test. Assessing weight capacity and volume displacement are also not the primary focus of a hydrostatic test. These aspects are more related to the design and specifications of the cylinder rather than its immediate safety and integrity under pressure. Overall, the hydrostatic test is crucial for ensuring that the dive cylinder is safe for use and can withstand the pressures experienced during diving activities.