Class Agenda
1. Purpose of Hydrotesting & Mechanical Stress Relief
- We will explore why hydrostatic testing is performed—not only to detect design or fabrication issues such as leaks or structural weaknesses, but also to facilitate mechanical stress relief within the vessel
2. Understanding Key Design Terminology
These terms will be clarified and applied throughout the session:
- Design Pressure – the maximum intended operating pressure of the vessel.
- MAWP (Maximum Allowable Working Pressure) – the highest pressure at which the vessel may be safely operated.
- MAP (Maximum Allowable Pressure) – sometimes used to denote the maximum permissible internal pressure based on nominal thickness minus corrosion allowance
- LSR (Lowest Stress Ratio) – the ratio of allowable stress at test temperature to allowable stress at design temperature. It is the lowest such ratio among materials used
3. ASME Section VIII-1, UG-99: Hydrostatic Test Requirements
- We’ll comprehensively review UG‑99, including:
- The requirement for hydrostatic testing as a condition for U‑stamping pressure vessels
- The calculation formula:
This session promises to equip you with both theoretical understanding and practical insights into hydrostatic testing as per ASME standards.