Applying the ASME Codes: Plant Piping & Pressure Vessels (Mister Mech Mentor, Vol. 2)
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- Ris (Zotero)
- Reference Manager
After construction, but before initial startup of mechanical piping systems, process vessels and storage tanks, the building construction and industrial safety and health codes nearly always require some sort of physical-integrity testing to be performed, witnessed, and passed. The test purpose is quite simple; to show that the vessel will hold the intended operational pressure without deforming excessively and without losing fluid containment. Any material, design, and construction flaws that might cause physical breakage of the vessel under pressure, or which might permit leakage, are thus detected under controlled conditions, and can be corrected and retested if necessary. This procedure is commonly called “hydrotesting,” but the prefix “hydro-” implies “water” or “liquid,” and that can be misleading. Pressure tests may not involve liquids at all, and that fact is a main reason for discussing pressure testing in this book.
(The systems excepted from pressure testing regulationsare both small and innocuous, posing no significant health or safety hazards. That does not exempt them from common-sense leak-testing before startup, or sanitary testing per health andplumbing codes, etc., of course. So don't insulateanything before at least doing a good leak-test on it! Thermal insulation is as brutally expensive the second time around as the first, and can cost the culprit his job as well!)
The various pressure-test regimens are typically well-defined in the applicable construction codebooks, and are governed under the auspices of state and local regulations. These regulations in turn are ultimately based upon legally adopted professional codes, which have historically been compiled from a mixture of scientific principles, engineering knowledge and experimentation, common sense and real-world experience.