1、Designation:G6214Standard Test Methods forHoliday Detection in Pipeline Coatings1This standard is issued under the fixed designation G62;the number immediately following the designation indicates the year of originaladoption or,in the case of revision,the year of last revision.Anumber in parentheses
2、 indicates the year of last reapproval.Asuperscriptepsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 These test methods cover the apparatus and procedurefor detecting holidays in pipeline type coatings.1.2 Method A is designed to detect holidays such as pin-hole
3、s and voids in thin-film coatings from 0.025 to 0.254 mm(1 to 10 mils)in thickness using ordinary tap water and anapplied voltage of less than 100 V d-c.It is effective on filmsup to 0.508 mm(20 mils)thickness if a wetting agent is usedwith the water.It should be noted,however,that this methodwill n
4、ot detect thin spots in the coating.This may be consideredto be a nondestructive test because of the relatively lowvoltage.1.3 Method B is designed to detect holidays such aspinholes and voids in pipeline coatings;but because of thehigher applied voltages,it can also be used to detect thin spotsin t
5、he coating.This method can be used on any thickness ofpipeline coating and utilizes applied voltages between 900 and20 000 V d-c.2This method is considered destructive becausethe high voltages involved generally destroy the coating at thinspots.1.4 The values stated in SI units to three significant
6、deci-mals are to be regarded as the standard.The values given inparentheses are for information only.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
7、 practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:3A742/A742M Specification for Steel Sheet,Metallic Coatedand Polymer Precoated for Corrugated Steel Pipe3.Terminology3.1 Definitions:3.1.1 holiday,nsmall faults or pinholes tha
8、t permit currentdrainage through protective coatings on steel pipe or polymericprecoated corrugated steel pipe.3.1.2 mil,n0.001 in.3.2 Definitions of Terms Specific to This Standard:3.2.1 holiday detector,na highly sensitive electrical de-vice designed to locate holidays such as pinholes,voids,andth
9、in spots in the coating,not easily seen by the naked eye.These are used on the coatings of relatively high-electricalresistance when such coatings are applied to the surface ofmaterials of low-electrical resistance,such as steel pipe.3.2.2 pipeline type coating,ncoatings of relatively high-electrica
10、l resistance applied to surfaces of relatively low-electrical resistance,such as steel pipe.4.Summary of Test Methods4.1 Both methods rely on electrical contact being madethrough the pipeline coating because of a holiday or alow-resistance path created by metal particles,or thin spots inthe coating.
11、This electrical contact will activate an alarmalerting the operator of the incidence of a holiday.4.2 In Method A,the applied voltage is 100 V d-c or less.4.3 In Method B,the applied voltage is 900 to 20 000V d-c.5.Significance and Use5.1 Method AMethodAdescribes a quick,safe method fordetermining i
12、f pinholes,voids,or metal particles are protruding1These test methods are under the jurisdiction of ASTM Committee D01 onPaint and Related Coatings,Materials,and Applications and are the directresponsibility of Subcommittee D01.48 on Durability of Pipeline Coating andLinings.Current edition approved
13、 July 1,2014.Published July 2014.Originally approvedin 1979.Last previous edition approved in 2013 as G62 07(2013).DOI:10.1520/G0062-14.2This was taken from the pamphlet“Operating Instructions for Tinker and RasorModel EP Holiday Detector.”Other manufacturers holiday detectors can beexpected to have
14、 similar voltage specifications.3For 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 B
15、arr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 through the coating.This method will not,however,find anythin spots in the coating.This method will determine theexistence of any gross faults in thin-film pipeline coatings.5.2 Method BMethod B describes a method for determ
16、in-ing if pinholes,voids,or metal particles are protruding throughthe coating,and thin spots in pipeline coatings.This methodcan be used to verify minimum coating thicknesses as well asvoids in quality-control applications.6.Apparatus6.1 Low-Voltage Holiday DetectorA holiday detector tes-ter having an electrical energy source of less than 100 V d-c,such as a battery;an exploring electrode having a cellulosesponge dampened with an electrically conductive liquid suchas tap water;and an audio indic
