ASTM G6-07(R2020) pdf free download

ASTM G6-07(R2020) pdf free download.Standard Test Method for Abrasion Resistance of Pipeline Coatings
1. Scope
1.1 This test method of accelerated test is a procedure for determining the relative resistance of steel pipeline coatings to abrasion by a slurry of coarse abrasive and water. The method is intended to apply to the testing of all types of electrical insulating pipeline coatings and tapes, including thermoplastics, thermoset, and bituminous materials. 1.2 Pipeline coatings are not normally subjected to the type of abrasion herein specified. 1.3 Metallic protective coatings such as zinc may be com- pared visually, but do not meet the electrical requirements of this test method. 1.4 The values stated in SI units to three significant deci- mals are to be regarded as the standard. The values given in parentheses are for information only. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appro- priate safety, health, and environmental practices and deter- mine the applicability ofregulatory limitations prior to use. 1.6 This international standard was developed in accor- dance with internationally recognized principles on standard- ization established in the Decision on Principles for the Development of International Standards, Guides and Recom- mendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
3. Terminology
3.1 Definitions: 3.1.1 holidays, n—small faults or pinholes which permit current drainage through protective coatings on steel pipe.
4. Summary of Test Method
4.1 Apparatus and materials are described whereby coatings on steel pipe are worn away by an abrasive slurry contained in a horizontally revolving drum. Specimens extend through both ends of the drum and are electrically insulated from contact with the test apparatus. 4.2 Periodic measurement of the electrical resistance be- tween the specimen and the drum indicates the degree of abrasion resistance of the coating.
5. Significance and Use
5.1 This procedure defines a test method for comparing the relative resistance of pipeline coatings to abrasion. 5.2 Abrasion resistance may be used to specify optimum coating thickness of candidate materials both in development and research work to study new coating systems or methods and in quality control.
6. Apparatus
6.1 Drum—A cylindrical steel container suitable for testing nine specimens simultaneously. Figs. 1-3 show construction details which may be altered at the cap assembly if desired. A valve shall be provided to release any pressure built up during test. 6.2 Apparatus for Revolving the Drum—Any suitable appa- ratus used to revolve the drum at 30.48 m (100 linear ft)/min. A modified jar rolling mill 4 has been found satisfactory for revolving the drum. 6.3 Thickness Gage, to be used in accordance with Test Method G12. 6.4 Holiday Detectors, low-voltage wet-sponge type for thin film coatings (coatings thinner than 20 mils), and high- voltage type for thick film coatings (coatings thicker than 20 mils). N OTE 1—Low voltage detectors are used to locate pinholes, voids, or thin spots in pipeline coatings. The potential used with wet-sponge detectors can be up to 100 V DC. Procedures for using these detectors are found in Method A of G62. For use of high voltage detectors operating in the 900 to 20 000 Vdc range, see Method B of G62. 6.5 Volt-ohm-meter—Any electrical test instrument for mea- suring electrical resistance of the circuit.
12. Precision and Bias
12.1 Precision data are limited to two adjacent specimens taken from the same production-coated pipe, assuming that the production process was uniform with respect to pipe surface condition and coating material. Specimens that were not adjacent in the as-produced condition, or were taken from different lengths of pipe may represent differing process conditions. 12.2 Repeatability—When more than one test of the same coating material is involved, the standard deviation of the results should not be greater than 1.0 times the hourly time interval between inspections for the specific coating material. The standard deviation 6 of a set of numbers is the square root of the average of the squares of the deviations of the numbers from their average. The standard deviation of two or more specimen results may be found by the following procedure.