ASTM_G_17_-_07_2013.pdf

Designation:G1707(Reapproved 2013)Standard Test Method forPenetration Resistance of Pipeline Coatings(Blunt Rod)1This standard is issued under the fixed designation G17;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 indicates the year of last reapproval.Asuperscriptepsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This accelerated test method is used to determine therelative resistance of steel pipeline coatings to penetration ordeformation by a blunt rod under a specified load.The testmethod is intended to apply to the testing of all types ofnonmetallic pipeline coatings subjected to various tempera-tures.1.2 The values stated in SI units to three significant deci-mals are to be regarded as the standard.The values given inparentheses are for information only.1.3This 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.Summary of Test Method2.1 The depth or rate of penetration or deformation that iscaused by a weighted blunt rod to a coating system applied tosteel pipe is measured over a period of time with a micrometerdepth gage.Three consecutive identical readings taken atspecified intervals conclude the test.3.Significance and Use3.1 Since pipeline coatings are subjected to concentratedpressures exerted by the weight of the pipe and the backfill,thistest is intended primarily for determining the resistance of thecoating to penetration or deformation under controlled condi-tions.3.1.1 Deformation of a compressible coating does not sig-nify a potential weakness in underground burial service,if thecoating is not penetrated.Deformation cannot be compared topenetration into and through a coating.4.Apparatus4.1 Test apparatus shall consist of a dead weight tester thatcan press the flat tip of a rod against the coated pipe.Theflat-tipped end of the rod contacting the coating shall have adiameter of 6.350 mm 6 0.0254 mm(0.250 in.6 0.001 in.)and together with supplementary weight and any other weight-contributing parts shall have a total weight of 4.453 kg(9.817lb),resulting in a unit pressure of 14.060 kg/cm2(200 psi)against the coating.Detailed design of the apparatus is shownin Figs.1-6 and Tables 1-4 show dimensions.4.2 Depth Gage,a device capable of measuring the penetra-tion movement of the rod accurately to 0.0254 mm(0.001 in.).4.3 Temperature Chamber,a thermostatically controlledenclosure to provide heating and cooling of the specimen andtest apparatus(excluding depth gage)to within 62C(3.6F)of the desired test temperature.This equipment is optionalwhen the test can be run within 62C(3.6F)of the desiredtest temperature without its use.4.4 Temperature Controlled Box,to fully enclose the testapparatus except the indicating means of the depth gage,asoptional equipment in cases where a test is to be run at atemperature higher than room temperature.The enclosure shallbe thermostatically controlled,capable of maintaining thetemperature to within 62C(3.6F)of the test temperature,which normally will be in the range of 23 to 76.6C(73.4 to170F).4.5 Thermometer,a temperature measurement device accu-rate to 60.5C(61F).5.Test Specimens5.1 The test specimens shall be 150 mm(6 in.)long andprepared with its surface preparation and coating proceduresequivalent to that of production coated pipe.Duplicate testsshall be run.6.Conditioning6.1 The specimen shall be exposed to the test temperaturefor a period of 24 h before beginning the test.If the testtemperature is the same as room temperature,it shall be 21 to25C(70 to 77F).7.Procedure7.1 Perform the test at room temperature or at the selectedtemperature.1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee D01.48 on Durability of Pipeline Coating and Linings.Current edition approved June 1,2013.Published June 1,2013.Originallyapproved in 1971.Last previous edition approved in 2007 as G17 07.DOI:10.1520/G0017-07R13.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 7.2 Accurately measure the thickness coating in the area tobe tested.Assemble the sample and end plates.Position thesample in the test unit so that the known film thickness area isdirectly under the weighted rod and hold the sample in positionby use of the cap screws.7.3 Loosen the shaft collar and allow the weight to rest onthe shaft guide.Using the depth gage take a measurementwithout the load applied.Raise the weight and tighten the setscrew in the collar so that the weight rests on the shaft.7.4 Take measurements every 24 h.7.5 Continue the test until the maximum pene