Factor design

The factors are listed which were involved in the final pipeline design and layout. Pertinent individual factors are then discussed in subsequent sections. Main divisions are as follows. 

The diameters of pipe were determined by the throughput of effluent. The new landline is in two diameters, 1000 and 1200 mm, and collects effluent at manholes, into which the existing outfalls were diverted. The old outfalls to the river were retained as overflows from the manholes, to allow for excessive storm water conditions (Fig. 24.2). The sea outfall is 500 mm OD, narrowing at the diffuser end, 2.2 km out to sea, to extend the flow of effluent. 

Butt welding was a fairly automatic choice for the joining together of individual lengths of pipe. It was a well tried and proven technique. However, a number of possibilities existed for the making of joints between fabricated butt-welded strings for the sea outfall. 

This involved the procedure for taking the pipeline 2.2 km out to sea, without damaging it. 

The wall thickness of the sea pipe was dependent on the internal pressure at which the effluent was to be pumped. 

Based on factors such as cast, mechanical properties, physical properties, ease of fabrication (design) and the corrosion resistance data available in the literature the choice of materials can lead to a short list of two or three materials. At this stage it is prudent that the engineer design prototype laboratory scale model equipment from the short-list of selected metals or alloys, and determine the corrosion rates in the environment of interest. These accelerated tests will enable the engineer to select the best candidate material, making proper allowance for the corrosion of the metal or alloy over the lifetime of the equipment. 

After selection of the material, the corrosion scientist must play a role in designing the equipment so that the design is appropriate, and avoids corrosion modes due to inappropriate design. Improper design may result in galvanic corrosion, crevice corrosion, 

Materials Aromatic Aliphatic Halogenated Ketones Alcohols Amines and salt Strong Strong Strong 

No effect or inert 2slight effect 3mild effect 

Test environment1 cone, reagent, wt % Temperature °C (°F) Si/SiC composites (12% Si) Tungsten carbide (6% Co) Alumina (99%) Silicon carbide (No free Si) 

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Another design factor is the position in which the weld must be made, which identifies the general orientation of the surface or of the axis of the... 

Vehicle Fa.ctors. Because knock is a chemical reaction, it is sensitive to temperature and reaction time. Temperature can in turn be affected either by external factors such as the wall temperature or by the amount of heat released in the combustion process itself, which is directiy related to the density of the fuel—air mixture. A vehicle factor which increases charge density, combustion chamber temperatures, or available reaction time promotes the tendency to knock. Engine operating and design factors which affect the tendency to produce knocking are... 

In actual practice, mechanical and electrical design factors usually require the cables to have layers of a certain thickness such that the electrical stress is far below the dielectric breakdown poiat. 

System rehabihty is improved by providing alternative means for performing the same task. For example, automobiles were equipped with hand cranks even though they had electric starters. This back-up equipment was provided because at that time starters were unrehable. In contemporary system design, factors such as added cost, weight, and space may prohibit the use of redundant systems. 

Product design factors overall part size shape complexity critical dimensions weight limitations potential for parts integration assembly requirements secondary operations Materialfactors... 

Some design factors, however, work against composites. For example, glass fiber-reinforced plastics generally have lower modulus (stiffness) than metals. Thickness and shape adjustments are requited where stiffness is a critical design requirement. With appropriate reinforcement, any modulus, even greater than that of metals, can be achieved. However, it may become expensive and uneconomical to do so. 

The conductivity of the grid plays a substantial role in a battery s abiUty to meet high current demands. The importance of grid conductivity for lead—acid batteries has been discussed (1,69). Composition and configuration are important design factors impacting grid conductivity. 

Pneumatic-Conveying Devices See Sec. 21 for descriptions, ratings, and design factors on these devices. Use is primarily for transport purposes, and heat transfer is a very secondary consideration. 

More often than not the rate at which residual absorbed gas can be driven from the liqmd in a stripping tower is limited by the rate of a chemical reaction, in which case the liquid-phase residence time (and hence, the tower liquid holdup) becomes the most important design factor. Thus, many stripper-regenerators are designed on the basis of liquid holdup rather than on the basis of mass transfer rate. 

The plate thickness of bubble-cap and sieve plates is generally estabhshed by mechanical design factors and has little effect on pressure drop. For a sieve plate, however, the plate is an integral component of the vapor-dispersion system, and its thickness is important. 

Fair s empirical correlation for sieve and bubble-cap trays shown in Fig. 14-26 is similar. Note that Fig. 14-26 incorporates a velocity dependence (velocity) above 90 percent of flood for high-density systems. The correlation implicitly considers the tray design factors such as the open area, tray spacing, and hole diameter through the impact of these factors on percent of flood. 

Operation of a traversing sampler for gravity flow of material for through-stream sampling is required to meet the following design factors ... 

Locating now in their respec tive scales on Nomograph 4 the design factor (from Nomograph 3) and the calculated equivalent lengm, draw an extended straight line to intersect the pivot line in the center. Now connect this point in the pivot line with the solids-ratio scale (from Nomograph 2), and read the system ressure loss. 

For EPSR design, the stress level to contain an explosion is set at the yield strength, a design factor of 1. Thus, for an alloy, the design stress level would be about 1.5 times the ASME code design stress. So a pressure vessel rated at 6 bar for the ASME code (EPR) would have an EPSR rating of 9 bar. 

The choice of a turboexpander load may be influenced by the desire to optimize refrigeration. In other words, a dynamometer load may be chosen over a generator load due to speed considerations. Additionally, there are other constraints imposed on optimal design. Factors such as impeller peripheral velocity (tip speed), bearing design, axial load balance, material selection, and manufacturing methods (which have greatly improved in the recent decades) all have an influence. 

Designing the output filter choke La) in a forward-mode converter is done first. This simple procedure can be seen in Section 3.5.5. A key design factor is to design the inductor to operate in the continuous current mode. The typical value of peak inductor current is 150 percent of the rated output current. The typical valley (minimum) current is about 50 percent of the rated output current. 

MW is die molecular weight K is die design factor HS is die hygiene standard. 

The selection of humidifiers or dehumidifiers must not be taken lightly, as many design factors have to be considered to ensure economic owning and operating costs. 

Power anil. A power unit shall consist of a bare engine, plus other equipment such as a fan for air cooling, special water pumps, and so forth. When included, specific information must be given as to design factors such as ambient temperature and power consumption. 

Design Factor. The design safety factors shall be calculated as follows (see Figure 4-12) for the relationship between the design safety factor and rating ... 

Care of Wire Rope in Service. The recommendations for handling a reel should be observed at all times during the life of the rope. The design factor should be determined by the following ... 

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