1、Designation:F72118An American National StandardStandard Specification forGage Piping Assemblies1This standard is issued under the fixed designation F721;the number immediately following the designation indicates the year of originaladoption or,in the case of revision,the year of last revision.Anumbe
2、r in parentheses indicates the year of last reapproval.Asuperscriptepsilon()indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S.Department of Defense.1.Scope1.1 This specification covers details of gage piping assem-blies
3、 for pressure gages with optional provisions for additionalgages,pressure switches,transmitters,and so forth,for usewith steam,steam drains,feed water,condensate,fresh water,salt water,compressed air,fuel oil,and lubricating oil systems.1.2 The values stated in inch-pound units are to be regardedas
4、standard.The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.3 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decisi
5、on on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2A105/A105M Specification for Carbon Steel Forgings forPiping ApplicationsA106/A106M Spe
6、cification for Seamless Carbon Steel Pipefor High-Temperature ServiceA108 Specification for Steel Bar,Carbon and Alloy,Cold-FinishedA182/A182M Specification for Forged or Rolled Alloy andStainless Steel Pipe Flanges,Forged Fittings,and Valvesand Parts for High-Temperature ServiceA276 Specification f
7、or Stainless Steel Bars and ShapesA335/A335M Specification for Seamless Ferritic Alloy-Steel Pipe for High-Temperature ServiceA576 Specification for Steel Bars,Carbon,Hot-Wrought,Special QualityB16/B16M Specification for Free-Cutting Brass Rod,Barand Shapes for Use in Screw MachinesB61 Specification
8、 for Steam or Valve Bronze CastingsB62 Specification for Composition Bronze or Ounce MetalCastingsB75 Specification for Seamless Copper TubeB124/B124M Specification for Copper and Copper AlloyForging Rod,Bar,and ShapesB453/B453M Specification for Copper-Zinc-Lead Alloy(Leaded-Brass)Rod,Bar,and Shape
9、sB466/B466M Specification for Seamless Copper-NickelPipe and Tube2.2 ANSI Standards:3B16.11 Forged Steel Fittings,Socket Weld,and ThreadedB16.15 Cast Bronze Threaded Fittings2.3 SAE International:4AMS-QQ-S-763 Steel,Corrosion Resistant,Bars,Wire,Shapes,and Forgings3.List of Assemblies3.1 This specif
10、ication incorporates 13 gage piping assem-blies as described in Table 1.4.General Requirements and Guidelines4.1 Fig.1 shows a typical piping assembly for bottom-connected gages and Fig.2 a typical piping assembly forback-connected gages.4.2 A siphon shall be used as shown in all gage applicationsfo
11、r steam systems to maintain a protective water seal betweenthe gage and the steam supply.4.3 Each assembly includes a test connection beyond thegage valve which consists of a tee with a14-in.NPT threadedplug in the branch.The plug is removable for the purpose ofinstalling a test gage for calibration
12、.As an alternative,a gagevalve that incorporates a built-in test connection integral withthe valve may be substituted for the gage valve and test tee.1This specification is under the jurisdiction of ASTM Committee F25 on Shipsand Marine Technology and is the direct responsibility of Subcommittee F25
13、.11 onMachinery and Piping Systems.Current edition approved May 1,2018.Published May 2018.Originallyapproved in 1981.Last previous edition approved in 2014 as F721 81(2014).DOI:10.1520/F0721-18.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serv
14、iceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.3Available from American National Standards Institute(ANSI),25 W.43rd St.,4th Floor,New York,NY 10036.4Available from SAE International(SAE),400 Commonwealth Dr.,Warrendale
15、,PA 15096,http:/www.sae.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for
16、theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.1 4.4 Root connections should be kept to a minimum byconnecting other instruments at the tee between the root andgage valves.There is no limit to the number of dead-end-typeinstruments that can be served from a single root connection.However,each instrument should have its own shutoff valveand,if desired,a test tee may be fitted at each instrument.