Oxygen Track: Electrolysis, Gases and Pressure Systems · Module 4 of 4 · about 15 min
Pressure systems and pipefitting
Gas plants are pressure systems. Pipe, valves, regulators and relief devices all have pressure ratings, and the whole line is only as strong as its weakest part. Relief valves are the last defense against overpressure, so they are never blocked, gagged or set above design.
New or repaired lines get pressure tested before service. Hydrostatic testing with water is preferred where possible because water stores far less energy than compressed gas; if something fails, a hydro test leaks, while a pneumatic test can explode. Pneumatic tests need extra controls and a cleared area.
Large plants handling highly hazardous chemicals above set amounts fall under OSHA's Process Safety Management standard, 1910.119. PSM requires process hazard analyses, written operating procedures, training, mechanical integrity programs and management of change, so that nobody swaps a part or a procedure without checking what it does to safety.
Watch the oxygen level wherever you work. OSHA treats air below 19.5 percent oxygen as oxygen-deficient and above 23.5 percent as oxygen-enriched in confined spaces. A personal monitor pays for itself the first time it alarms.
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Module quiz
5 questions, 4 correct to pass. You'll see what you missed and why, and you can retake it.