Used Materials of Construction

Code Sec. II Part D for a full listing of materials properties and AS ME BPV Code Sec. VUI Div.l for material-specific fabrication guidelines. 

trade names and codes are given by Perry et al. (1997). A comprehensive review of the engineering materials used for chemical and process plant can be found in the book by Evans (1974). 

Low carbon steel (mild steel) is the most commonly used engineering material. It is cheap, is available in a wide range of standard forms and sizes, and can be easily worked and welded. It has good tensile strength and ductility. 

The carbon steels and iron are not resistant to corrosion, except in certain specific environments, such as concentrated sulfuric acid and the caustic alkalis. They are suitable for use with most organic solvents, except chlorinated solvents, but traces of corrosion products may cause discoloration. 

Mild steel is susceptible to stress corrosion cracking in certain environments. 

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Understand process and do not use materials of construction that may lead to problems... 

Use materials of construction that enhance inherently safer operations. Corrosion leads to leaks incompatible materials can lead to unwanted reactions. 

Cooling water required on site often is stored in towers storage tank problems or piping and valve malfunctions could cause loss of this component. If seawater is used, materials of construction must be more resistant to salt. Loss of steam purchased or generated in water tube boilers could result from boiler lube failure, turbine failure, or piping or valve malfunction. 

When equipment uses materials of construction other than carbon steel, or operating temperatures are extreme, the capital cost needs to be adjusted accordingly. Whilst the equipment cost and its associated pipework will be changed, the other installation costs will be largely unchanged, whether the equipment is manufactured from carbon steel or exotic materials of construction. Thus, the application of the factors from Tables 2.2 to 2.6 should only be applied to the equipment and pipework ... 

The intensity of seismic motion that can be tolerated by various kinds of structures must be established before acceptable charge weights at various distances can be determined. Obviously, the level of motion required to damage a structure depends upon its construction. For example, a steel-framed warehouse can tolerate a more. intense seismic wave than a residential structure with plaster walls. Because plaster is the weakest of the most commonly used materials of construction, and because of the prevalence of such structures, most damage criteria are based oh this type of structure... 

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. 

Whilst carbon and stainless steels are commonly used materials of construction, increasing use is being made of non-metallic and rubber lined equipment. The selection of the material of construction should take into account the cases of the worst process conditions that may occur under foreseeable conditions and should be applied to all components including valves, pipe fittings, instruments and gauges. Both composition (e.g., chlorides, moisture) and temperature deviations can have a significant direct effect on the rate of corrosion. The operator should demonstrate that procedures are in place to ensure that potential deviations in process conditions such as fluid temperature, pressure and composition are identified and assessed in relation to the selection of materials of construction for piping systems. 

Cupro-Nickels. At the present time, most marine operators agree that the cupro-nickels are the most useful material of construction for sea-water plants. Since World War II, the 90 Cu-10 Ni alloy modified with about 1.5% of iron has become well established. The lower nickel content results in a cost advantage over the 70 Cu-30 Ni alloy. Alloys containing 70 Cu-30 Ni or 80 Cu-20 Ni, each with added iron, are preferred by some designers to withstand more severe conditions. 

Recently, aluminum has been demonstrated to be a very useful material of construction for sea-water plants. Special care must be taken with aluminum to avoid contact with most other metals. Heavy metal ions in the incoming sea water, such as copper, must be removed before the water enters an aluminum installation to prevent local attack such as pitting. 

The facilities engineer must consider the materials used to construct the wetted parts of the unit operations used to treat the waste. The goal is to select a cost-effective material that will not degrade in the presence of the waste stream to be treated. In general, the most commonly used materials of construction for the unit operations are 316or316L stainless steel. However, if chlorides, fluorides, and other halogens are present in the CMP chemistry, it may be necessary to consider nickel, titanium, Hastelloy, or other high-performance metals. 

This is a huge general category of materials, which includes both thermoplastics and thermosetting polymers. Tabular data on the corrosion resistance of these materials in a wide range of environments are available from a variety of sources. Commonly used materials of construction in the CPI include polyvinyl chloride (PVC and CPVC), polyethylene, polypropylene, polystyrene, polycarbonate, polytetrafluoroethylene (PTFE), fiberglass composite materials, and a variety of epoxies used for coatings or adhesives. 

Carbon steels are the most widely used materials of construction. Unalloyed carbon steels typically contain nominal amounts of manganese, silicon, phosphorus, and sulfur. They are normally supplied with a pearlitic-ferritic microstructure (see Figure 21.3) produced by air cooling a hot-formed product (e.g., hot-rolled plate) or by a normalizing heat treatment. They are available as either killed carbon steel or plain carbon steel. 

Materials of construction. It is necessary to use materials of construction for this separation that resist corrosion at the high concentrations of HCl used in the process. The Bureau of Mines plant [Ml] used glass columns, ass- or rubber-lined equipment, and rubber tubing connectors. The British plant [Jl] used polythene mixer-settlers. 

In the manufacture of fine chemicals, SS-304/SS-316/SS-316L is a commonly used material of constructions. For other duties, special materials such as SS-304 ELC, glass lined, fiber reinforced plastic (FRP), graphite, etc. may be required to counter... 

A candle filter contains a number of cylindrical elements in a vertical tank, using materials of construction similar to those used in leaf filters. The elements can be built up, in modules similar to those used in mist eliminators (Section 9.1.5), or they can be solid cylinders made of carbon or a ceramic. The latter are porous, with walls about... 

The designer of an evaporator system must have a fundamental knowledge of the properties and applications of common materials of construction and of the corrosive effects of common chemicals. He must also be familiar with the basic standards and practices for using materials of construction. This basic knowledge should enable the designer to ... 

It is felt that timely and correct procurements of the right type of equipments/ machineries with all the reqtrired features and constmcted with the appropriate (suitable for the intended use) materials of construction (MOC) can ertsure a smooth and safe scheduled start-up of the project at the budgeted cost (or minimising cost overruns). 

Carbon steel is the most widely used material of construction. It is the primary material of choice for bridges, towers, various types of structures, and other types of outdoor constructions. In nature, iron is found in the form of various oxides, which are used as ores for refining to make steel. Steels in atmospheric service therefore tend to return to their oxide form by the process known as rusting. The rusting of steel is the most common form of corrosion that the general public sees, but it is very complex, having over a dozen variables determining the rate of corrosion. Water is the most common corrosive solvent. 

Retest periods may vary depending upon use, material of construction, and the cylinder specification. Many steel cylinders must be retested every 5 years. DOT and TC regulations allow for specification 3A and 3AA cylinders to be retested every 10 years provided the cylinder meets the regulatory criteria in 49 CFR 173.34, which are summarized in CGA P-15, Filling of Industrial and Medical Nonflammable Com-... 

Tooling. Forming operates primarily under the force of gravity and low-pressnre vacnnm, so structural requirements for molds are minimal. Because the plastic is kept below its melting point, cooling requirements are also minimal or nonexistent. Wood is a commonly used material of construction for forming, while higher performance molds can be constracted from nickel-coated epoxy or from electroformed nickel shells. 

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