Selection and Designation

Valve Bubble Tight Throttle Where Used Pig Pressure Drop Size 

Plug Yes No On/Off Isolation Rare No Low Rare Cheaper than ball 

Gate Yes Some Control, wellhead isolation, doubloLlock bleed Yes Low 2 -Up Larger sizes cheaper than ball 

Check No No To restrict reversal of flow Isolation Swing check Valves only some cases Low /. -tp  

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Walas, S. M., Chemical Process Equipment Selection and Design, Butterworth, Reading, Mass., 1988. 

Many successful types of reactors are illustrated throughout this section. Additional sketches may be found in other books on this topic, particularly in Walas Chemical Process Equipment Selection and Design, Butterworths, 1990) and Ullmann Encyclopedia of Chemical Technology (in German), vol. 3, Verlag Chemie, 1973, pp. 321-518). 

Below, we analyse the likely fault levels of a system under different circuits and fault conditions for an easy understanding of the subject. It is a prerequisite to decide the level of fault, to select and design the right type of equipment, devices and components and the protective scheme for a particular network. 

Fig. 1.1. A fully working model, one- sixth full size, of a steam traction engine of the type used on many forms a hundred years ago. The model con pull on automobile on a few litres of water and a handful of cool. But it is also a nice example of materials selection and design.

SELECTION AND DESIGN OF TURBOCOMPRESSORS FOR NITRIC ACID PLANTS... 

Chandra, U. 1997 Control of Residual Stresses. In ASM International, Handbook No. 20 Materials Selection and Design, 10th Edition, OH ASM International. 

This design example purposely avoids the use of a highly integrated buck controller IC. It would be instructional to show the selection and design process involved in a switching power supply. Refer to Figure 3-65... 

Table 12.1 Some considerations in reaction process selection and design...

Let s take the example of benzene, which at 12,000 ppm, is 100% LEL. The National Fire Protection Association (NFPA) states that equipment can operate, without LEL monitors or controls, if the LEL is less than 25% LEL. For benzene then, 25% LEL is equal to 3,000 ppm. This upper boundary becomes a dictating factor in the selection and design of the oxidation equipment. If the concentration is higher than 25% LEL, the NFPA requirements state that an LEL monitor is required. Using an LEL monitor, NFPA guidelines allow operation up to 50% LEL (a 2 1 safety factor). Thus, 100% LEL is explosive if the stream is at 25%, a factor safety of four exists. 

Knowledge of the process or operation and contaminant sources is essential before ventilation systems can be selected and designed. Contaminant sources affecting the working environment may be external, associated with the elements of HVAC systems, or internal. 

Elame propagation can also be stopped between process eqnipment handling bnlk solids and powders by jndicions selection and design of bnlk solids/powders conveying eqnipment snch as rotary valves (rotary airlocks) and screw conveyors. The mass of bnlk solids/powders contained in these items of eqnipment provide a tortnons path throngh which the gas and flame have to pass, and so can act as a material choke when certain design features are implemented. 

Selection and Design Criteria/Considerations r- APPROACHING FLAME FRONT... 

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