FLUID TRANSPORT EQUIPMENT

Standard pipe is made in a discrete number of sizes that are designated by nominal diameters in inches, as inches IPS (iron pipe size). Table A5 lists some of these sizes with dimensions in inches. Depending on the size, up to 14 different wall thicknesses are made with the same outside diameter. They are identified by schedule numbers, of which the most common is Schedule 40. Approximately, 

Tubing for heat exchangers, refrigeration, and general service is made with outside diameters measured in increments of 1/16 or 1/8 in. Standard size pipe is made of various metals, ceramics, glass, and plastics. 

More than 100 manufacturers in the United States make valves that may differ substantially from each other even for the same line size and pressure rating. There are, however, independent publications that list essentially equivalent valves of the several manufacturers, for example the books of Zappe (1981) and Lyons (1975). 

Control valves have orifices that can be adjusted to regulate the flow of fluids through them. Four features important to their use are capacity, characteiislic, rangeability and recovery. 

Over a threefold load change, the performances of linear and equal percentage valves are almost identical. When the pressure drop across the valve is less than 25% of the system drop, the equal 

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Absence of moving parts and simphcity of construction have frequently justified the use of jets and eductors. However, they are relatively inefficient devices. When air or steam is the motivating fluid, operating costs may be several times the cost of alternative types of fluid-transport equipment. In addition, environmental considerations in todays cnemical plants often inhibit their use. 

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