High pressure hazards pressurized vessels, rupture

Two major hazards may occur from high pressure vessel failures. The vessel itself may rupture and the formation of vapor cloud as a result of the rupture is possible. If the vessel ruptures, it will produce flying projectiles and usually release large quantities of vapors, and in the case of most hydrocarbons are combustible.The projectiles could harm individuals or damage the process facility, possibly increasing the incident proportions. Secondly, the release of a combustible gas from a pressurized vessel may cause the formation of combustible vapor cloud, which if a suitable amount of congestion is present or some turbulence of the cloud occurs, an explosive blast may result once the cloud contacts an ignition source. 

Although microwave-heated organic reactions can be smoothly conducted in open vessels, it is often of interest to work with closed systems, especially if superheating and high-pressure conditions are desired. When working under pressure it is strongly recommended to use reactors equipped with efficient temperature feedback coupled to the power control and/or to use pressure-relief devices in the reaction vessels to avoid vessel rupture. Another potential hazard is the formation of electric arcs in the cavity [2], Closed vessels can be sealed under an inert gas atmosphere to reduce the risk of explosions. 

Safeguards reduce the magnitude of either the consequence or the predicted frequency term (they do not remove the hazard). For example, a berm/bund wall around T-lOO reduces the consequences of a spill from the tank. The pressure relief valve on V-101 reduces the likelihood that the vessel will rupture due to high pressure. 

Description of hazard. A pressure vessel is a cylindrical or spherical metal container capable of withstanding pressures exerted by the contained material. Many liquids and gases must be stored under high pressure in such vessels. Safety codes have been developed that specify the container design for specified conditions, with special emphasis on the strength of the vessel to prevent rupture and subsequent explosions. All shells, test chambers, tanks, and model parts designed for internal pressures greater than 15 pounds per square inch (psi) are considered pressure vessels. 

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