_RP_550-1-8-1980_scan.pdf

API RECOMMENDED PRACTICE 550FOURTH EDITION,OCTOBER 1980Manual on Installation of RefineryInstruments and Control SystemsPart I-Process Instrumentation and ControlSection 8-Seals,Purges,and Winterizing621-7G62.8AME3242Manual on Installation of RefineryInstruments and Control SystemsPart I-Process Instrumentation and ControlSection 8-Seals,Purges,and WinterizingAPI RECOMMENDED PRACTICE 550FOURTH EDITION,OCTOBER 1980春oNERLIBRARY分食292RECEIVED(l hdat a,American Petroleum Institute2101 L Street,NorthwestWashington,D.C.20037Manual on Installation of RefineryInstruments and Control SystemsPart I-Process Instrumentation and ControlSection 8-Seals,Purges,and WinterizingRefining DepartmentAPI RECOMMENDED PRACTICE 550FOURTH EDITION,OCTOBER 1980OFFICIAL PUBLICATIONREG US PATENT OFFICEFOREWORDThis recommended practice is based on the accumulated knowledge and experience ofengineers in the petroleum industry.Its purpose is to aid in the installation of the moregenerally used measuring,control,and analytical instruments;transmission systems;andrelated accessories to achieve safe,continuous,accurate,and efficient operation withminimum maintenance.Although the information has been prepared primarily forpetroleum refineries,much of it is applicable without change in chemical plants,gasolineplants,and similar installations.Successful instrumentation depends upon a workable arrangement that incorporates thesimplest systems and devices that will satisfy specified requirements.Sufficientschedules,drawings,sketches,and other data should be provided to enable the constructorto install the equipment in the desired manner.The various industry codes and standardsand laws and rulings of regulating bodies should be followed where applicable.For maximum plant personnel safety,transmission systems are employed to eliminatethe piping of hydrocarbons.acids,and other hazardous or noxious materials toinstruments in control rooms.Proper installation is essential in order to use fully thecapabilities that are built into the instrument or transmission system.In the installation of an instrument,the various components must be accessible forefficient maintenance,and certain of these elements must be readable for good operationOrifices,control valves,transmitters,thermocouples,level gages,and local controllers,as well as analyzer sample points.generally should be readily accessible from grade,permanent platforms,or fixed ladders.In this manual,special consideration is given to thelocation,accessibility,and readability of the elements.Users of this manual are reminded that in the rapidly advancing field of instrumentationno publication of this type can be complete nor can any written document be substitutedfor qualified engineering analysisCertain systems are not covered in this section because of their highly specialized natureand limited use.When one of these systems gains general usage and installation reaches afair degree of standardization,this section will be revised to incorporate such additionalinformation.Acknowledgment is made to all the engineers and operating and maintenance personnelwho,through years of study,observation,invention,and sometimes trial and error,havecontributed to the technology of instrumentationSuggested revisions are invited and should be submitted to the director of the RefiningDepartment,American Petroleum Institute,2101 L Street,N.W.,Washington,D.C.20037.