Steel constructions protection

NFPA requirements state that if equipment or process vessels, columns of tanks are suitably constructed of substantial steel construction adequately grounded, and do not give off flammable vapors, no other mechanism of lighting protection is required. This is also true of flares, vent stacks and metal chimneys by nature of their construction and grounding facilities. 

Compressors should preferably be located outdoors or, alternatively, in buildings of totally noncombustible construction with adequate ventilation. Concrete or concrete-on-protected-steel should be used for a compressor system supporting structure. Exposed steel construction is acceptable if protected by water spray or deluge system. 

Zinc dust coatings are utilized in large quantities for the protection of structural steel, also including underwater steel construction and ship building [5.56]. Zinc dust is used in organic and inorganic binder systems (alkali silicates, ethyl silicates) [5.56, 5.105]. 

Coating Systems for Corrosion Protection of Large Steel Constructions (Heavy-Duty Coatings) [ii i],[ii.2]... 

Figure 10.21 Schematic description of a cathodic protection device. Power source (1), steel construction (2), and inert anodes (3).

The special case of the bimetallic effect between a zinc coating and the substrate that it is protecting is discussed under hot water aqueous corrosion resistance as the normal bimetallic effect whereby zinc protects steel is reversed in some waters, usually at 60-90°C. Bimetallic corrosion of zinc occurs mainly when zinc or zinc-coated steel is protecting uncoated steel or other base metals such as copper. Many of the uses of zinc deliberately invoke this principle, but in other cases an unwanted effect arises as a result of constructional requirements, and avoidance of bimetallic corrosion is needed. 

Knotkova, D., Hasil, F., and Barton, K. (1975). Racionaini ochrana ocelovych konstrukci proti atmosfericke korozi (Efficient protection of steel constructions from atmospheric corrosion). Strojirenstvi, 25(10), 597-609 (in Czech). 

Wijngaard, B. H. (1971). Cathodic Protection of Steel Constructions in Seawater. Economic Choice of Galvanic Anodes. Dutch Institute for Applied Scientific Research (TNO), Metaalinst, Delft, Netherlands, Publication 196, 6 pp. 

Carbon and low-alloy steels are the predominant alloys used for construction of waterfront structures. In most applications the steels are protected by protective coatings in the atmospheric, splash, and intertidal zones (including metallic and elastomeric sheathing) and are protected by either cathodic protection alone or by a combination of coatings and cathodic protection in the immersion zone. Use of stainless steels is limited predominantly to mechanical applications rather than structural applications. The use of stainless steel fasteners is common. 

Treat with a second solvent, simply attach a pressure-capable tank to the work chamber to store, dispense, and recover the second solvent. With an enclosed machine, there is no reason for the semi-aqueous process as low-cost hydrocarbon and terpene-based SA solvents can be used, contained, and evaporated at any temperature. If in the unlikely event that the second solvent must be water, one should use construction materials of 315 stainless steel for protection against corrosion, and implement a desiccant dryer (Chapter 3.7.7). 

Priifung von Duplexsystemen zum Korrosionschutz von Stahlkonstruktionen dutch Feuerverzinken und Beschichten (Testing of duplex systems for the corrosion protection of steel constructions by hot-dip galvanising and coating) (in German), January 1985 Werkst. Korros. 38 (1987) 3, p. 135... 

Steel Construction Institute. Protection of piping systems subject to fires and explosions, UK HSE research report 285, Her M gesty s Stationery Office, Norwich, UK ... 

Every material in use is exposed to a certain environment which can influence or destroy the function of components. Corrosion causes much damage to steel constructions. Corrosion must always to be considered as a system of two reactants - metal and corrosive environment. The cause of all corrosion reactions is the thermodynamic instability of metals in relation to different environments, such as air, water, acids or other oxidizing agents. Kinetic barriers such as protective layers or passive films make a metal more or less inert to most environments. Stainless steels derive their good corrosion resistance from the thin invisible passive film of chromium oxide formed by reaction between the metal and oxygen in the ambient environment. 

These options also depend on a number of factors, of which open steel construction is not always the more favourable, although a simple steel construction certainly does not involve as much procurement cost as the closed method of construction. Due to stronger environmental influence on machines in the case of open construction, electrical equipment, for example, has to be designed in a higher protection class, thus leading to higher procurement costs. The extent of environmental effects, however, is closely related to the climatic conditions. 

Such a luxury insulation is necessary only if the heterogeneous assembly is immersed (or located in an area that will retain water), and provided that safety rules do not obUge the use of a common grounding. In this case, the common grounding will transform the immersed aluminium structures into sacrificial anodes for the cathodic protection of steel constructions. 

In all branches of the industry, including the manufacture of cars and other forms of transportation (bus, truck, and rail), construction companies, shipyards and chemical plants, particular strategies for corrosion protection have been developed and all use, to some extent, organic coatings with active pigments. Some of them, for example, in steel construction, use coating systems similar to that shown in Fig. 1.2, where zinc particles act as an active pigment. 

Seawater and the atmosphere above seawater are extremely corrosive environments. Organic coatings are widely used to protect steel constructions in these cases, so the choice and buildup of the coating system are often illustrative of the possibilities of protection by organic coatings [49]. 

Current control can be more advantageous where rail/soil potentials are predominantly positive. Current control is also preferred in the cathodic protection of steel-water construction if the anode resistance fluctuates due to changes in electrical conductivity. 

The protection of aluminum ships demands particular attention since electrical contact with steel and copper materials can seldom be avoided and a whole range of aluminum alloys are unsuitable for cathodic protection (see Section 2.4 and Fig. 2-11). Later protective measures must therefore be observed during the construction stage since even good coatings in combination with cathodic protection are frequently not adequate to protect gaps or openings. 

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