_RP_550-1-12-1977_scan.pdf

API RP 550园MANUALONINSTALLATION OF REFINERY INSTRUMENTSAND CONTROL SYSTEMSPART I-PROCESS INSTRUMENTATION AND CONTROLSECTION 12-CONTROL CENTERSTHIRD EDITION1977522.323AMEFOREWORDThis recommended practice is based on the accumulated knowledge and experi-ence of engineers in the petroleum industry.Its purpose is to aid in the installationof the more generally used measuring,control,and analytical instruments;trans-mission systems;and related accessories in order to achieve safe,continuous,accu-rate,and efficient operation with minimum maintenance.Although the informa-tion contained herein has been prepared primarily for petroleum refineries,muchof it is applicable without change in chemical plants,gasoline plants,and similarinstallations.Successful instrumentation depends upon a workable arrangement that incorpo-rates the simplest system and devices that will satisfy specified requirements.Suffi-cient schedules,drawings,sketches,and other data should be provided to enablethe constructor to install the equipment in the desired manner.The various indus-try codes and standards,and laws and rulings of regulating bodies should be fol-lowed where applicable.The information contained in this publication does notconstitute,and should not be construed to be,a code of rules or regulations.For maximum plant personnel safety,transmission systems are employed toeliminate the piping of hydrocarbons,acids.and other hazardous or noxious ma-terials to instruments in control rooms.Proper installation is essential in order toutilize the full capabilities which are built into the instrument or transmission system.In the installation of an instrument,the various components must be accessiblefor efficient maintenance and certain of these elements must be readable for goodoperation.Orifices,control valves,transmitters,thermocouples,level gages,andlocal controllers,as well as analyzer sample points,generally should be readilyaccessible from grade,permanent platforms,or fixed ladders.In this manual,special consideration is given to the location.accessibility,and readability of theelements.Users of the various sections of this manual are reminded that in the rapidlyadvancing field of instrumentation no publication of this type can be complete,norcan any written document be substituted for qualified engineering analysis.Certain systems are not covered herein because of their very specialized natureand limited use.When one of these systems gains general usage and installationreaches a fair degree of standardization,this section will be revised to incorporatesuch additional information.Acknowledgment is made of the work of all the engineers and operating andmaintenance personnel who,through years of study,observation,invention,andsometimes trial and error have contributed to the technology of instrumentation.Suggested revisions are invited and should be submitted to the director of theRefining Department,American Petroleum Institute,2101 L Street,N W.,Wash-ington,D.C.20037.的