ASTM_D_1066_-_11.pdf

Designation:D106611Standard Practice forSampling Steam1This standard is issued under the fixed designation D1066;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 sampling of saturated andsuperheated steam.It is applicable to steam produced in fossilfired and nuclear boilers or by any other process means that isat a pressure sufficiently above atmospheric to establish theflow of a representative sample.It is also applicable to steam atlower and subatmospheric pressures for which means must beprovided to establish representative flow.1.2 For information on specialized sampling equipment,tests or methods of analysis,reference should be made to theAnnual Book of ASTM Standards,Vols 11.01 and 11.02,relating to water.1.3 The values stated in SI units are to be regarded asstandard.The values given in parentheses are for informationonly.1.4 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:2A269 Specification for Seamless and Welded AusteniticStainless Steel Tubing for General ServiceA335/A335M Specification for Seamless Ferritic Alloy-Steel Pipe for High-Temperature ServiceD1129 Terminology Relating to WaterD3370 Practices for Sampling Water from Closed ConduitsD5540 Practice for Flow Control and Temperature Controlfor On-Line Water Sampling and Analysis3.Terminology3.1 Definitions:3.1.1 For definitions of terms used in this practice,refer todefinitions given in Practice D1129.3.2 Definitions of Terms Specific to This Standard:3.2.1 isokinetic sampling,na condition wherein thesample entering the port(tip)of the sampling nozzle has thesame as the velocity vector(velocity and direction)as thestream being sampled.Isokinetic sampling ensures a represen-tative sample of dissolved chemicals,solids,particles,chemi-cals absorbed on solid particles,and in the case of saturatedand wet steam,water droplets are obtained.3.2.2 sample cooler,na small heat exchanger designed toprovide cooling/condensing of small process sampling streamsof water or steam.3.2.3 sampling,nthe withdrawal of a representative por-tion of the steam flowing in the boiler drum lead or pipeline bymeans of a sampling nozzle and the delivery of this portion ofsteam in a representative manner for analysis.3.2.4 saturated steam,na vapor whose temperature cor-responds to the boiling water temperature at the particularexisting pressure.3.2.5 superheated steam,na vapor whose temperature isabove the boiling water temperature at the particular existingpressure.4.Summary of Practice4.1 This practice describes the apparatus,design conceptsand procedures to be used in extracting and transportingsamples of saturated and superheated steam.Extraction nozzleselection and application,line sizing,condensing requirementsand optimization of flow rates are all described.Condensedsteam samples should be handled in accordance with PracticesD3370 and D5540.5.Significance and Use5.1 It is essential to sample steam representatively in orderto determine the amount of all impurities(dissolved chemicals,solid particles,chemicals absorbed on solid particles,water1This 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 June 15,2011.Published July 2011.Originallyapproved in 1949.Last previous edition approved in 2006 as D1066 06.DOI:10.1520/D1066-11.2For 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 droplets)in it(1).3An accurate measure of the purity of steamprovides information,which may be used to determine whetherthe purity of the steam is within necessary limits to preventdamage or deterioration(corrosion,solid particle erosion,flow-accelerated corrosion,and deposit buildup)of down-stream equipment,such as turbines.Impurities in the steammay be derived from boiler water carryover,inefficient steamseparators,natural salt solubility in the steam and other factors.The most commonly specified and analyzed parameters aresodium,silica,iron,copper,and cation conductivity.6.Interferences6.1 Saturated SteamSampling of steam pre