ASTM_D_5540_-_13.pdf

Designation:D554013Standard Practice forFlow Control and Temperature Control for On-Line WaterSampling and Analysis1This standard is issued under the fixed designation D5540;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This practice covers the conditioning of a flowing watersample for the precise measurement of various chemical andphysical parameters of the water,whether continuous or grab.This practice addresses the conditioning of both high-andlow-temperature and pressure sample streams,whether fromsteam or water.1.2 This practice provides procedures for the precise controlof sample flow rate to minimize changes of the measuredvariable(s)due to flow changes.1.3 This practice provides procedures for the precise controlof sample temperature to minimize changes of the measuredvariable(s)due to temperature changes.1.4 The values stated in SI units are to be regarded asstandard.The values given in parentheses are mathematicalconversions to inch-pound units that are provided for informa-tion only and are not considered standard.1.5 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D1066 Practice for Sampling SteamD1129 Terminology Relating to WaterD3370 Practices for Sampling Water from Closed ConduitsD3864 Guide for On-Line Monitoring Systems for WaterAnalysis3.Terminology3.1 DefinitionsFor definitions of terms used in thispractice,refer to Terminology D1129.3.2 Definitions of Terms Specific to This Standard:3.2.1 approach temperature,nthe difference in tempera-ture between cooling water temperature in and sample tem-perature out.3.2.1.1 DiscussionThis term is used in heat exchangerapplications and applies to all types of heat exchangers.Theterm is defined as:the difference between the outlet tempera-ture in one stream and the inlet temperature in the other stream.3.2.2 crud deposition,non interior surfaces of sampletubing or other hardware,the disposition of fine insolubleparticles(of iron oxides and other byproducts of metalliccorrosion)that are present throughout the system.3.2.2.1 DiscussionThe term“crud”is generally used forall types of fouling.3.2.3 sample conditioning,nreduction of the temperatureand pressure of a flowing sample from process conditions to acontrolled temperature and pressure,and maintenance of aconstant flow rate both in incoming sample lines and throughon-line analyzers.3.2.4 sample cooler,na small heat exchanger designed tocool small streams of water or steam.3.2.5 temperature compensation,nby the use of electronicadjustment or data manipulation,the adjustment of the ana-lyzers measured temperature for variation in sample tempera-ture from a preestablished value.4.Summary of Practice4.1 This practice covers the system design,operatingprocedures,and selection of equipment to help ensure theappropriate flow and temperature control for analysis of waterand steam samples.This control is essential to ensure theaccuracy and repeatability of on-line analyzers.Variations intypes of analysis,sample characteristics,and their effect onsample conditioning are included.4.2 The equipment and procedures described in this practiceare intended to represent current state-of-the art technologyavailable from major manufacturers of sample conditioning1This practice is under the jurisdiction of ASTM Committee D19 on Water andis the direct responsibility of Subcommittee D19.03 on Sampling Water andWater-Formed Deposits,Analysis of Water for Power Generation and Process Use,On-Line Water Analysis,and Surveillance of Water.Current edition approved July 15,2013.Published July 2013.Originallyapproved in 1994.Last previous edition approved in 2008 as D5540 08.DOI:10.1520/D5540-13.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 equipment.Refer to Practices D1066 and D3370 and GuideD3864 for additional information on sampling.5.Significance and Use5.1 Sample conditioning systems must be designed to ac-commodate a wide range of sample source temperatures andpressures.Additionally,efforts must be made to ensure that theresultant sample has not been altered during transport andconditioning and has not suffered excessive transport delay.Studies have shown that sample streams will exhibit minimaldeposition of