Explosion relief

In reciprocating compressors, the use of explosion-relief devices must be stated if desired. The type and style of distance piece must be specified together with the connections for the collection and disposal of leakage gas. API 618 gives a rather complete coverage of all options. 

Safety devices, e.g. PSVs, explosion reliefs, trips Monitoring and control instruments... 

A flammable vapor explosion in a vessel initially at atmospheric pressure can create a pressure of 10 atmospheres (NFPA 69, 1992, Section 5-3.3.1). A weak process vessel requires substantial vent area for vapor-air explosion relief. 

After three months of operation, an explosion occurred in a 400 m3 tank, which fortunately was fitted with explosion relief. Three weeks later another explosion blew the roof off another tank, and the Australian Department of Mines ordered the closure of the plant. 

HSE (Health and Safety Executive). 1980. Guide for Flame Arresters and Explosion Reliefs. Booklet HS(G)11. Health and Safety Executive, Her Majesty s Stationery Office, London, England. 

Figure 7-8R. Low pressure bursting vents for explosion relief on storage silos, buildings, etc. Usually burst 1.0 to 8.0 psig depending on design. Round vents also available. By permission, Fike Metal Products DIv., Fike Corporation, Inc.

When a flammable liquid is sprayed as fine droplets into the air, a flammable mixture can result, which may burn or explode. The mist or spray may be formed by condensation of saturated vapors or by mechanical means [40]. As the particle sizes of the liquid become greater than 0.01 mm diameter, the lower flammability limit of the material becomes lower while above 0.01 mm, the LEL is about the same as the vapor. Mechanical engine crankcase explosions of oil mist in air are hazardous, and current practice is to apply explosion relief valves to the crankcase. 

Flame Arrestors and Explosion Reliefs. The flame trap is constructed of strips of corrugated and flat steel ribbon wound in a spiral. It breaks up a flame in the very small passages between the corrugations where the flame is quenched and extinguished. 

Provide pressure relief and explosion relief (or suppression) and systems for emergency venting where relevant... 

Precautions recommended include use of cold zinc and total enclosure of such processes [2]. The possibility of explosions of zinc dust suspended in air is presented as a serious hazard [3], A serious dust explosion in the air filter unit of a zinc grinding mill was initiated by a spark from an explosion relief panel [4], See Zinc chloride, below... 

Ducts Explosion Relief, Fire Protection, Relief Devices Adequacy, Vent Size, Discharge,... 

For some other types of emergency relief, such as dust explosion relief of relatively weak vessels, it is common practice to size the relief system to limit the pressure to that which will cause deformation but not failure of the vessel. If an explosion occurs, the deformed vessel can be replaced. Great care should be taken before applying such principles to pressure vessels for the following reasons ... 

Starch dust can produce an extremely explosive mixture with air. All motors in confined areas must have explosion-proof ratings. The silo and all conveying equipment must be grounded to eliminate static electricity. Furthermore, starch silos must be equipped with an explosion relief deck to provide an escape route in case of a dust explosion. Another requirement is a vacuum relief valve to prevent the silo from caving in, in case a starch bridge in the silo suddenly collapses. The starch content in the... 

Explosion relief for vapor-air combustion within a closed top low-pressure tank cannot be accomplished by customary tank conservation vents or other light-weight protection. A well-written brief description of safety features of low-pressure tanks can be found in... 

Pumps Ducts Conveyors, mills Procedures Piping Relief, reverse, rotation, identification of materials of construction Explosion relief, fire protection and support Stop devices, coasting and guards Spills, leaks and decontamination Rating, codes, cross-connections and materials of construction... 

The NFPA 68 guide issued in 19987 has nomographs, which can be used to select relief areas required for combustible dusts when test data on the dusts are available. The nomographs in NFPA 68 are considered by many to be the preferred way to design dust explosion relief devices. 

Therefore, in the absence of explosion relief, the deflagration explosion of a hydrocarbon-air mixture is easily capable of bursting a vessel if it is operating near its design pressure when the deflagration takes place. For reactions... 

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