A pressure vessel is a closed container or storage tank that is designed to hold materials such as gasses or liquids at high pressures. Some types of pressure vessels include compressed gas storage tanks (air, oxygen, nitrogen tanks, etc.), anhydrous ammonia tanks, hydro pneumatic tanks, autoclaves, hot water storage tanks, chemical reactors and refrigerant vessels. They are designed for operating pressures above 15 pound-force per square inch gauge (psig) and a volume greater than 5 cubic feet or 1 ½ cubic feet in volume with a pressure exceeding 600 psig. The pressure of the contained material is substantially different from the pressure of the surrounding environment, or ambient pressure. The pressure differential presents dangerous circumstances and safety hazards; therefore the need for proper handling is crucial.
Care and caution are required to avoid serious safety issues, fatal accidents have occurred in the past during vessel development and operation. Due to the dangerous nature of pressure vessels, legislation has appointed engineering authorities to regulate the pressure vessel design, manufacture, handling and operation. Pressure vessels must be installed, operated and maintained in accordance with standards and codes of the industry. Compliance is absolutely imperative in order to protect the safety and health of workers.
Pressure vessels must pass a multitude of inspections. If a pressure vessel is cracked or damaged it creates number of health and safety hazards. When pressure vessels fail, it is usually catastrophic, releasing large amounts of energy and contents. Some possible reactions are high-speed projectiles or a shock wave of the vessel contents. Suffocations, poisonings, fires and explosions are also possible. These situations can have devastating consequences and the potential dangers are extensive. Inspections help prevent such accidents from happening, but proper maintenance between inspections is equally as important. Proper knowledge of local and federal mandates for pressure vessels is