Piping national standards

Identification of Piping Systems, American National Standards Institute, New York, A13.1,1981 Chemical Plant and Refiney Piping, B31.3,1990 Precautionay Eabeling of Ha rdous Industrial Chemicals, Z129.1,1988. 

Standard Chemical Pump. In 1961, the American National Standards Institute (ANSI) iatroduced a chemical pump standard (29), known as ANSI B73.1, that defined common pump envelope dimensions, connections for the auxiUary piping and gauges, seal chamber dimensions, parts mnout limits, and baseplate dimensions. This definition was to ensure the user of the availabiUty of iaterchangeable pumps produced by different manufacturers, as well as to provide plant designers with standard equipment. A typical ANSI chemical pump, known as of the mid-1990s as ASME B73.1M-1991, is shown ia Figure 6. 

The ferrous-metal piping systems comprising wrought carbon and alloy steels including stainless steels are the most widely used and the most completely covered by national standards. 

Extracted from the American National Standard for Ductile-Iron Pipe, CentrifugaUy Cast in Metal Molds or Sand-Lined Molds, for Water or Other liquids, ANSI A21.51—1976, with permission of the piihlisher, the American Society of Mechanical Engineers, New York. 

American National Standards Institute (ANSI), formerly American Standards Association (ASA). ANSI promulgates the piping codes used in the chemical-process industries. 

The most common schedule in use is 40, and it is useful for a wide range of pressures defined by ANSI Std. B 36.1 (American National Standards). Lighter wall thickness pipe would be designated Schedules 10, 20, or 30 whereas, heavier wall pipe would be Schedules 60, 80, 100, 120, 140, 160 (see Appendix Table). Not all schedules are in common use, because after Schedule 40, the Schedule 80 is usually sufficient to handle most pressure situations. The process engineer must check this schedule for both pressure and corrosion to be certain there is sufficient metal wall thickness. 

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. 

Equipment manufacturers also work to standards to produce standardised designs and size ranges for commonly used items such as electric motors, pumps, pipes and pipe fittings. They will conform to national standards, where they exist, or to those issued by trade associations. It is clearly more economic to produce a limited range of standard sizes than to have to treat each order as a special job. 

Details of the standard pipe fittings, welded, screwed and flanged, can be found in manufacturer s catalogues and in the appropriate national standards. The standards for metal pipes and fittings are discussed by Masek (1968). 

Usually C02 pipelines are designed using existing national standards for gas and liquid transportation pipes, while additional C02 specific design issues are taken into consideration by the pipeline construction/operation companies to guarantee the reliable and safe operation of a given pipeline. 

All materials for process equipment and piping should be identifiable and conform, where necessary, to the requirements of the ASTM(1) or other national standard specifications. Table A-1 contains typical ASTM standard specifications for different product forms in frequent use. 

Many chemical and petroleum companies are now using Process Industry Practices (PIP) criteria for the development of P IDs. These criteria include symbols and nomenclature for typical equipment, instrumentation, and piping. They are compatible with industry codes of the American National Standards Institute (ANSI), American Society of Mechanical Engineers (ASME), Instrument Society of America (ISA), and Tubular Exchanger Manufacturers Association (TEMA). The PIP criteria can be applied irrespective of whatever Computer Assisted Design (CAD) system is used to develop P IDs. Process Industries Practice (1998) may be obtained from the Construction Industry Institute mentioned in the References. 

ASME Code for Pressure Piping, B31, An American National Standard. Chemical Plant and Petroleum Refinery Piping. The American Society of Mechanical Engineers New York, 1986... 

Pipes containing phosgene should be plainly labelled in accordance with the appropriate National Standards. Shut-off valves should be conspicuously labelled, and containers which are in use should be suitably marked. 

Many piping specifications are partially established by consensus standards such as the American National Standards Institute (ANSI), ANSI B31.3, Chemical Plant and Petroleum Piping Code, the American Petroleum Institute s (API) API 5L Specifications for Lined Pipe, or the National Fire Protection Association s (NFPA) NFPA 30 Flammable and Combustible Liquids Code. These can form the foundation for specifications however, individual plant operating conditions and history should be considered when establishing piping specifications. ... 

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