Use Corrosion Resistant Materials

Use corrosion resistant material of construction Implement mechanical integrity program to prevent leaks of corrosive material Use multiple voting with plausibility analysis... 

For these special situations properly designed rupture disks using corrosion-resistant materials can be installed both before the valve inlet as well as on the valve discharge. For these cases, refer to both the valve manufacturer and the rupture disk manufacturers. See later discussion of code requirements for this condition. 

In the last decade, some systems, such as the Dionex DX-500, have been manufactured with a flow path using corrosion-resistant materials such as polyetheretherketone (PEEK , ICI Americas Wilmington, DE), rather than the traditional stainless steel. Since stainless steel is prone to corrosion by salts, particularly halides, the introduction of titanium, ceramic, and PEEK was welcomed by those performing chromatography in aqueous systems, particularly in biological applications. PEEK , however, is not useful in applications requiring pressures greater than about 4000 psi. 

The stainless steels are the most frequently used corrosion resistant materials in the chemical industry. 

By using corrosion-resistant material in constructing the well... 

Use Corrosion Resistant Materials. Some of the sludge generated is the result of corrosion or deterioration of the storage tank internals. Installation of a liner or using materials of construction which are more resistant to the corrosive elements of crude oil reduces sludge production. 

Figure 4-6. Austenitic stainless steels are most widely used corrosion resistant materials.

There are means to combat low-temperature corrosion using corrosion resistant materials. All these means do not contribute to an improvement in the availability of the entire installation. Often a lower efficiency than would be economically justified is accepted, just because of availability considerations. 

Marine sedimenfs sometimes possess unusual characferisfics nof found in most terrestrial soils and therefore special procedures musf be utilized, for example, many marine clays are very soff compared to those usually encountered in geotechnical engineering practice. The presence of salfwafer requires special considerations in almost all testing procedures and it is best to use corrosive-resistant materials for test... 

Only filtered water should be used for acid cooling and it should not contain more than 50 ppm of dissolved solids. Regular blow downs of cooling tower basins are recommended to control the TDS level. Since the presence of chlorides in cooling water makes it corrosive, the acid coolers can be constructed using corrosion resistance materials like Hastelloy C-276. 

HMIS Health 3, Flammability 0, Reactivity 1 Storage Store in cool, dry, well-ventilated area, out of direct sunlight deliq. avoid generating mists limit quantities in use use corrosion-resist, materials hygroscopic, deliq. 

Corrosive wear can usually be identified by a pitted, worn surface. The best solution to corrosive wear is to eliminate the corrosive component from the compound. However, this is often not possible for other reasons. In this case, one has to use corrosion-resistant materials of construction, such as stainless steel. Inconel, Hastelloy, etc. In order to select the best material of construction, one should know the chemical species that are causing the corrosive attack. Various metal handbooks contain information about the chemical resistance of many metals against a number of chemical species. Figure 11.12 shows a flow chart that allows systematic troubleshooting of wear problems. 

Liquids. Approximately 170,000 railroad tank cars are used in the United States. The interior surfaces of these cars are tailored to carry a wide variety of products and are constmcted of steel which is either unlined or lined with materials to enhance the chemical compatibiUty with a specific product these lining materials include synthetic mbber, phenoHc or modified epoxy resins, or corrosion-resistant materials such as aluminum, nickel-bearing steel, or stainless steel. 

Polycarbonates. Polyarjiates are aromatic polyesters commonly prepared from aromatic dicarboxylic acids and diphenols. One of the most important polyarylates is polycarbonate, a polyester of carbonic acid. Polycarbonate composite is extensively used in the automotive industry because the resin is a tough, corrosion-resistant material. Polycarbonates (qv) can be prepared from aUphatic or aromatic materials by two routes reaction of a dihydroxy compound with phosgene accompanied by Hberation ofHCl(eq. 5) ... 

Packed vs Plate Columns. Relative to plate towers, packed towers are more useful for multipurpose distillations, usually in small (under 0.5 m) towers or for the following specific appHcations severe corrosion environment where some corrosion-resistant materials, such as plastics, ceramics, and certain metaUics, can easily be fabricated into packing but may be difficult to fabricate into plates vacuum operation where a low pressure drop per theoretical plate is a critical requirement high (eg, above 49,000 kg/(hm ) (- 10, 000 lb/(hft )) Hquid rates foaming systems or debottlenecking plate towers having plate spacings that are relatively close, under 0.3 m. 

The gas distribution system can be composed of a network of perforated pipe, slotted or vented concrete block, or metal grating. When there are no space hmitations, single-level filters are used. In regions where footprint space is hmited, hke Japan, multiple-deck filter beds have become commonplace. If inorganic compounds are being treated, corrosion-resistant materials of construc tion are used due to the acidic by-products of the bioreaction. 

Eveiy effort should be made to eliminate direct (Bourdon-type) pressure gauges. Diaphragm pressure gauges constructed of appropriate corrosion-resistant materials are preferred. Flow limiters should be used to limit flow in case of loss of integrity... 

Recently in some types of refuelling stations, corrosion-resistant materials have been used between the filter-water separator and the outlet pipeline and valves, usually stainless steel, rarely aluminum. If these are buried, they must have good insulating coating and be electrically separated from other tank installations by insulating couplings. 

The use of electrochemical protection in the chemical industry started about 20 years ago, which is somewhat recent, compared with its use for buried pipelines 40 years ago. Adoption was slow because the internal protection has to be tailored to the individual plant, which is not the case with the external protection of buried objects. Interest in internal protection came from the increasing need for greater safety for operating plants, increased demands for corrosion resistance, and larger plant components. While questions of its economy cannot generally be answered (see Section 22.6), the costs of electrochemical protection are generally less than the cost of equivalent and reliable coatings or corrosion-resistant materials. 

The use of corrosion-resistant materials and the application of corrosion protection measures are in many cases the reason that industrial plants and structures can be built at all. This is particularly so in pipeline technology. Without cathodic protection and without suitable coating as a precondition for the efficiency of cathodic protection, long-distance transport of oil and gas under high pressures would not be possible. Furthermore, anodic protection was the only protective measure to make possible the safe operation of alkali solution evaporators (see Section 21.5). 

The flexible element coupling requires no lubrication, which is a distinct advantage. The need for lubrication is always a problem with gear couplings. This advantage is partially offset in the flexible element by the need for corrosion-resistant materials for the normal chemical plant atmosphere. Inconel 718 and 15-5 PH have been used and have been rea-... 

The use of fully corrosion-resistant materials is not always the best choice. One must optimize the relation between capital investment and cost of subsequent maintenance over the entire estimated life of the equipment. 

These are used as corrosion-resistant materials. Examples are given in Table 3.32. Some can be strengthened by heat treatment. The alloys containing substantial amounts of silicon have the best foundry characteristics and a high resistance to corrosion, but are not readily machined. 

Although transformers suitable for other industrial installations are generally suitable for producing applications, certain options may be desirable— primarily due to environmental considerations. At locations subject to harsh environmental conditions, and particularly at locations subject to washdown with high-pressure hoses, non-ventilated enclosures are desirable, if not necessary. Likewise, at locations subjected to salt water and salt-laden air, it often is desirable to specify copper windings and lead wires. Most manufacturers provide standard units with aluminum windings and lead wires. Even if aluminum coils are used, it is almost always desirable to require stranded copper lead wires. This will lessen corrosion and loose terminal problems when transformers arc interconnected to the facility electrical system with copper conductors. If the transformers are to be installed outdoors in corrosive environments, cases should be of corrosion-resistant material (e.g., stainless steel) or be provided with an exterior coating suitable for the location. 

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