Atmospheres, classification

Electrical apparatus for explosive gas atmospheres Classification of hazardous areas 5572/1994 BS EN 60079-10/1996 ... 

FPN No. 1) As a guide in determining when flammable gases are present continuously, for long periods, or under normal conditions, refer to. Recommended Practice for Classification of Locations for Electrical Installations of Petroleum Facilities, API RP 500-1991, Electrical Apparatus for Explosive Gas Atmospheres, Classifications of Hazardous Areas, lEC 79-10 and. Institute of Petroleum Area Classification Code for Petroleum Installations, IP 15. 

ISO 9223 1992. Corrosion of metals and alloys. Corrosivity of atmospheres. Classification. 

ISO 9223, Corrosion of Metals and Alloys-corrosivity of Atmospheres-classification, Geneva, Switzerland ISO, 1992. 

ISO 9223 2012, Corrosion of Metals and Alloys—Corrosivity of Atmospheres—Classification, Determination and Estimation, International Organization for Standardization, ISO Central Secretariat, Geneva 20, 2012, Srvitzerland. 

BS EN 60079-10-2 2009 (2009) Explosive atmospheres. Classification of areas. Combustible dust atmospheres, Oct 2009... 

This system of atmospheric classification is now being revised to create a new approach based on dose-response functions for steel, copper, and zinc. Because the corrosion of aluminum occurs by a pitting or localized mechanism, the traditional approach of using mass loss to determine severity of attack is often misleading. Atmospheric corrosion problems with aluminum alloys are most frequently a result of metallurgical conditions rather than environmental conditions, and the behavior of aluminum may be excluded in the upcoming revision of the ISO 9223-6 documents. 

Considering the above, test sites should be selected to provide general corrosion performance in one or more of these atmospheric classifications. ASTM Committee G01.04 on Atmospheric Corrosion operates sites that include all three, and testing can be done in these providing the data accumulated become part of the public record. In addition, there are several private, government, and commercial testing facilities already established where exposure space can be rented. 

ISO Standard-Corrosion of Metals and Alloys-Corrosivity of Atmospheres-Classification (9223)... 

Corrosion of metals and alloys—Corrosivity of atmospheres—Classification... 

A method that would enable detection and classification of the bone content in 100% of the incoming frozen fish blocks in real time without delaying the production line was desired. An obvious solution to this was the use of X-ray inspection. X-ray inspection however requires the integration of a highly sensitive inspection equipment with the corrosive atmosphere associated with food processing as well as the tough restrictions imposed by the health authorities regarding irradiation of food. 

Ensure vents relieve to a safe location. If vented to atmosphere, ensure proper classification and controlled access... 

FPN No. 4) For classification of areas involving ammonia atmosphere, see Safety Code for Mechanical Refrigeration, ANSI/ASHRAE 15-1992, and Safety Requirements for the Storage and Handling of Anhydrous Ammonia, ANSI/CCA G2.1-1989. 

The classification given in Table 1.2 is based on the various forms that corrosion may take, but the terminology used in describing corrosion phenomena frequently places emphasis on the environment or cause of attack rather than the form of attack. Thus the broad classification of corrosion reactions into wet or dry is now generally accepted, and the nature of the process is frequently made more specific by the use of an adjective that indicates type or environment, e.g. concentration—cell corrosion, crevice corrosion, bimetallic corrosion and atmospheric corrosion. 

In a sense this subdivision of the composition of the atmosphere is arbitrary since some of the so-called contaminants are derived partly or wholly from natural sources. However, in that their concentrations vary appreciably within very narrow geographical limits, they may be distinguished from the contents of Table 2.8 (with the possible exception of water vapour). Table 2.6 lists those contaminants which are important from a corrosion standpoint. Excluded are contaminants found only in very specific locations, e.g. in the vicinity of a chemical works. The concentrations given are intended only to indicate general levels in the usual classification of environments and not to define a particular environment. 

Metals and alloys removal of corrosion products from corrosion test specimens Metals and alloys atmospheric corrosion testing general requirements for held tests Corrosion of metals and alloys. Classification of corrosivity of atmospheres Corrosion of metals and alloys. Guiding values for the corrosivity categories of atmospheres... 

Titanium, D. of as oxide, via tannic acid and phenazone complexes, (g) 470 by hydrogen peroxide, (s) 696 Titan yellow 692 Titrand 257 Titrant 257 Titration 257 classification of, 258 in an inert atmosphere, 376, 629 in non-aqueous solvents, 281 aniline (and ethanolamine), D. of, 307 indicators for, 283 solvents for, 283... 

Many estimates of total terrestrial net primary production are available, ranging between 45.5 Pg C/yr (Lieth, 1972) and 78 Pg/yr (Bazilevich et al., 1970). Ajtay ef oZ. (1979) have revised the various estimates and methods involved, they also reassess the classifications of ecosystem types and the extent of the ecosystem surface area using new data and arriving at a total NPP of 60 Pg C/yr. Gross primary production is estimated to be twice net primary production, i.e., 120 Pg C/yr. This implies that about 60 Pg C/yr are returned to the atmosphere during the respiratory phase of photosynthesis. It is well known that carbon dioxide uptake by plants follows daily cycles most plants take up CO2... 

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