Symbols, flow sheet/piping

Drawings should conform to accepted drawing conventions, preferably those laid down by the national standards. The symbols used for flow-sheets and piping and instrument diagrams are discussed in Chapter 4. Drawings and sketches are normally made on detail paper (semi-transparent) in pencil, so modifications can be easily made, and prints taken. 

American Standards Association graphical symbols are available foi piping detail work (see Fig. 9-2). Other useful symbols are shown r Fig. 3. One type of detailed equipment flow sheet is shown in Fig. 3-9... 

Separation processes typically consist of hrmdreds of elements (pipes, vessels, heat exchangers, columns, pumps, compressors, engines, measuring and control devices, etc.) that are too complex for exact graphical depiction. Therefore, the process structures are depicted in a very abstract and geometrically nonsimilar manner in the form of flow sheets. Flow sheets show the process structure with symbols for the essential process elements according to international standards (e.g., DIN, ISO). 

To understand the design and function of a chemical plant it is a useful preliminary to study the flow diagram (sometimes called a flow sheet). Its purpose is to illustrate diagrammatically, on one sheet of paper, all the items of equipment required for a chemical process or series of processes to be operated. Items are represented by simple symbols which are usually those recommended by the British Standard 974 1953 and subsequent editions (your supervisor may have a copy). The route of materials through the equipment is indicated by arrows and interconnecting lines and, in some instances, the materials of construction, size or capacity, flow rates, power requirements, and pipe dimensions are also shown. 

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