Estimating structural steel

Concrete and Structural Steel quantities can be easily checked with the quick estimating procedures in Chapter 19. 

Structural Steel - Use procedure in Section 19.3 to develop take-offs and cost. Break down by structures and pipe racks and don t forget to identify and estimate miscellaneous service ladders and platforms related to specific equipment items. 

At the condensing-reflux system in Figure 7-67, the elevation of the condensers is influenced by several factors. First, the reflux drum must be elevated because of pump NPSH requirements, say 14 feet to the bottom of the drum (about 2-3 feet below this elevation, a platform is required). To this 14 feet must be added the drum diameter, estimated space for pipe lines, depth of structural steel members plus platform-to exchanger-centerline dimension for establishing the exchanger elevation above grade. 

The objective is to predict corrosion initiation time for various cases using SimCorr . In this simulation, chloride is assumed present at the surface at aU times. The model simulations are used to determine corrosion initiation time and reinforcing steel rebar life in the deck and cap beam of the bridge. SimCorr can be used to predict corrosion initiation time as a function of stmctural and environmental parameters, estimate structure life, design concrete mixes, and geometry based on Hfetime calculations and optimize corrosion protection system as a function of surrounding conditions. SimCorr also serves as a tool for evaluation of chloride transport and underlying concrete corrosion. The simulation software is based on the first principles model described in [77]. 

As discussed for the depropanizer, Aspen IPE prepares the Capital Estimate Report, MCB.ccp, which contains detailed listings of the items to be procured to install the equipment (classified in the areas of piping, instrumentation, electrical, structural steel, and insulation), estimates of the man-hours required for installation, estimates of the costs, and an installation schedule. Estimates for contractor engineering and indirect costs are listed as well. 

The Master Curve methodology uses a mathematical model to describe the probability of cleavage fracture initiation in a material containing a distribution of postulated fracture initiators (flaws). The model includes the temperature dependence of Kj, which was estimated empirically from a data set including various ferritic structural steels. The scatter definition based on the Weibull distribution, the size adjustment and the definition of the temperature dependence are the basic elements of the Master Curve methodology as described in ASTM E 1921. 

It is estimated that disinantling and burial of N Reactor will involve more than 9,500 m (111,000 y[Pg.244]

Aluminium spraying of steel street-lighting columns has been used since the 1950s and it is estimated that one producer alone has supplied up to 200000 such columns repainting is simpler, even on neglected columns, than on columns not metal sprayed. Aluminium spraying has been used on reflector towers used in the television link between Manchester and Edinburgh, and on similar structures. 

PLATE 8 Corrosion is a chemical process whose results are easy to see in the world around us. In this picture, corrosion of reinforcing steel has caused the conerete pillars to spall, weakening the bridge and forcing the installation of wooden joists to temporarily support the bridge deck structure. The results of corrosion impose significant economic costs on society—in 1982, these eosts were estimated at about 120 billion. Courtesy, Robert Baboian, Texas Instruments, Inc. 

Cathodic deposition of lead sulfide from acidic aqueous solutions of Pb(II) ions (nitrate salts mainly) and Na2S203 on various metallic substrates at room temperature has been reported. Stoichiometric PbS films composed of small crystallites (estimated XRD diameter 13 nm) of RS structure were obtained at constant potential on Ti [204]. Also, single-phase, polycrystalline thin films of RS PbS were electrode-posited potentiostatically on Ti, Al, and stainless steel (SS) [205]. It was found that the Al and Ti substrates promoted growth of PbS with prominent (200) and (111)... 

Corrosion is the oxidative deterioration of a metal, such as the conversion of iron to rust, a hydrated iron(III) oxide of approximate composition Fe203 H20. The rusting of iron has enormous economic consequences. It has been estimated that as much as one-fourth of the steel produced in the United States goes to replace steel structures and products that have been destroyed by corrosion. 

After a period of time, objects made of iron or steel will become coated with rust. The rusting of iron is a serious problem and wastes enormous amounts of money each year. Estimates are difficult to make, but it is thought that upwards of 1 billion a year is spent worldwide on replacing iron and steel structures. 

Section 6.5 because of the detailed design information now available. The costing was done in accordance with the recommendations of Mu let, Corripio and Evans (Ref. Al 3). Their method utilizes correlations for the cost of a simple carbon-steel structure. Factors are then applied to account for the cost of other materials, the inclusion of trays, for operating pressure, and for incidentals such as ladders and railings. The cooling circuit was costed on the basis of heat-transfer area using similar correlations. Details of the cost estimation calculations are included in Appendix G.5. 

Some noteworthy similarities exist between wind energy systems and CPV systems.9 They both employ relatively common materials, particularly steel. Wind system costs are typically less than 1 per watt they depend mainly on the cost of steel, whereas flat-plate PV is linked to the availability and cost of expensive semiconductor silicon. But solar concentrator structures are also amenable to an auto-assembly type of production (see Fig. 5), and CPV developers estimate CPV production facility costs are much closer to those of wind systems than to those of flat-plate PV production facilities. In early EPRI cost studies, CPV production facility costs were estimated (on the same costing basis as the crystalline and amorphous silicon facilities) to be about 28 million for a 100 MW per year installation—about one-quarter the cost of the conventional silicon PV facilities.10 These lower investment costs can lead to a faster scale-up of manufacturing facilities because investor risk is relatively smaller than the risks entailed in investing in conventional PV production facilities. 

This procedure is used to estimate the weight, fabricated cost, and erection hours of the various types of steel structures required in a chemical plant. It is a very good tool for checking contractors take-offt and estimates as well as discussing and evaluating field extras. 

The initial capital investment for different capacity modules is illustrated in Figure 2. Represented here are the estimated budgetary selling prices for installed carbon steel units. However, unique installation costs, like site preparation, unusual foundations or support structures, interconnecting duct work, utility connections, or remote instrumentation are excluded. 

Other workers have published improved procedures for inspecting both reinforced concrete and prestressed concrete structures with regard to determination of the embedded steel components [110]. A prototype ultrasonic procedure was developed to determine the condition of prestressed and pretensioned tendons in concrete. The application of electrochemical surface-mounted systems for estimating the rate of corrosion of reinforcing steel and other embedded steel components in large concrete structures was described using this technique. 

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