1、Designation: G10 10 (Reapproved 2015)Standard Test Method forSpecific Bendability of Pipeline Coatings1This standard is issued under the fixed designation G10; the number immediately following the designation indicates the year of originaladoption or, in the case of revision, the year of last revisi
2、on. A number in parentheses indicates the year of last reapproval. A superscriptepsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This method covers the specific determination of theeffect of short-radius bends on coatings applied to 33.4-mm(1-in. nominal) di
3、ameter pipe.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.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility o
4、f 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:2G6 Test Method for Abrasion Resistance of Pipeline Coat-ingsG12 Test Method for Nondestructive Measurem
5、ent of FilmThickness of Pipeline Coatings on Steel (Withdrawn2013)33. Summary of Method3.1 The method consists of bending a 33.4-mm (1-in.nominal) diameter specimen of coated pipe around a mandrelto produce a range of short-radius bends. Coating failure in theform of cracking or loss of adhesion is
6、detected through visualand electrical inspection of the bent specimen.4. Significance and Use4.1 This test will provide information on the ability ofcoatings applied to pipe to resist cracking, disbonding, or othermechanical damage as a result of bending. Because the test isapplied to coated pipe fr
7、om commercial production, the resultscan be directly used in the selection of similar materials forservice. The test also has application as a quality controlmethod when variations in coating application or materialformulation will affect bending performance.5. Apparatus5.1 The bending apparatus sha
8、ll be essentially as shown inFigs. 1-3 and shall include the following:5.1.1 Variable-Radius Mandrel, constructed from four19-mm (0.75-in.) thick pieces of plywood, bolted together andconforming to the geometric shape shown in Fig. 1. Thegeometric construction is accomplished by laying out along the
9、outer edge of the mandrel a series of seven consecutive arcs atdecreasing radii of 610, 530, 460, 380, 300, and 230 mm (24,21, 18, 15, 12, and 9 in.). The first five arcs shall be carriedthrough a 45-deg angle to the next point of tangency. A 45-degV-notch shall be cut into the edge of the mandrel f
10、or seating thepipe specimen. Holes shall be drilled at appropriate locations inthe mandrel face for positioning the lever arm and fasteningpipe clamps.5.1.2 Lever Arm-Roller AssemblyA 1.83-m (72-in.) leverarm with nylon roller supplies the mechanical advantagenecessary to bend the pipe specimen. The
11、 lever arm shallcontain a series of holes which are used to maintain properclearance between the roller and pipe sample during thebending operation.5.2 Thickness GageMeasurements of coating thicknesswill be required for this test. This shall be done in accordancewith Test Method G12.5.3 Holiday Dete
12、ctorA low-voltage d-c holiday detectorof the wet-sponge type, specified in Test Method G6, shall beused to locate breaks in the coating film.6. Test Specimens6.1 The test specimen should be 2.5 m (100 in.) in length. Itshould be representative of production-coated pipe and be freeof obvious coating
13、flaws or defects. Coating specimens shall beapplied to 33.4-mm (1-in. nominal) diameter pipe.7. Conditioning7.1 The specimen shall be exposed to room temperature fora sufficient time to ensure thermal equilibrium in the pipe and1This test method is under the jurisdiction of ASTM Committee D01 on Pai
14、ntand Related Coatings, Materials, and Applications and is the direct responsibility ofSubcommittee D01.48 on Durability of Pipeline Coating and Linings.Current edition approved Dec. 1, 2015. Published December 2015. Originallyapproved in 1969. Last previous edition approved in 2010 as G10 10. DOI:1
15、0.1520/G0010-10R15.2For 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.3The last approved version of this histori
16、cal standard is referenced onwww.astm.org.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1coating. A temperature in the range from 20 to 30C (68 to85F) shall be considered room temperature.8. Procedure8.1 Perform the test at a room te
17、mperature of 21 to 25C (70to 77F).8.2 Measure the applied coating thickness of each specimenin accordance with Test Method G12.8.3 The time to execute the test at a uniform velocity shouldbe agreed upon by the producer and the user.8.4 Place the conditioned test specimen into the V-notch.Secure the
18、pipe in place with clamp No. 1 and tighten thethumb screw. Remove the threaded handle from clamp No. 1 toallow for clearance of the lever arm. With the steel pivot pin athole A of the lever arm (see Fig. 3), insert the pin into thesocket on the bed of the bending jig. Place the nylon roller atpositi
19、on C on the lever arm. Apply the roller to the pipespecimen, and with a constant, even force with the leverhandle, bend the pipe around the mandrel until the 460-mm(18-in.) radius bend has been made. Insert and secure pipeclamp No. 2. Continue bending the pipe until the 300-mm(12-in.) radius has bee
20、n reached. Insert and secure pipe clampNo. 3. Reposition the lever arm by moving the pivot pin to the25-mm (1-in.) diameter hole in the mandrel surface. Move thenylon roller to position B on the lever arm. Apply the roller tothe pipe and complete the bending operation by forming thespecimen through
21、the 230-mm (9-in.) radius.8.5 Examine the bent specimen with a wet-sponge holidaydetector to determine at what point, if any, cracking of thecoating film occurred. Note the number, size, location, and typeof cracks present. Examine the pipe specimen for any loss ofcoating bond caused by the bending
22、operation.NOTE 1The possibility of some coatings developing stress-inducedcracks in the period following the bending operation should not beoverlooked. If this is a consideration, the bent specimen should be retainedfor a 24-h post-bent inspection.FIG. 1 Variable-Radius MandrelFIG. 2 Details of Mand
23、rel Assembly and Support BracketsG10 10 (2015)29. Report9.1 The initial test report shall include the following:9.1.1 Complete identification of the coated pipe tested,including: name and type of coating, average coating thickness,minimum coating thickness, maximum coating thickness,manufacturers lo
24、t number, and date of manufacture.9.1.2 Temperature of the pipe specimen as tested,9.1.3 Radius at which cracking first occurred,9.1.4 Description of the type of cracking,9.1.5 Location and extent of any loss in pipe-to-coatingbond,9.1.6 Number of specimens tested,9.1.7 Any peculiar characteristics
25、of the specimen notedduring the test or after immediate removal from the testapparatus, and9.1.8 Post-bend retention time.10. Precision and Bias10.1 As this test method serves as a coating performanceguide to investigators wishing to compare the relative merits ofpipe-coating materials, no precision
26、 and bias statement isrequired.11. Keywords11.1 bendability; flexability; pipeline coatingsASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination
27、 of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdraw
28、n. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your co
29、mments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single o
30、r multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ 3 Details of Lever Arm and Pipe ClampsG10 10 (2015)3
