ASTM G20-10(R2019) pdf free download

ASTM G20-10(R2019) pdf free download.Standard Test Method for Chemical Resistance of Pipeline Coatings
1. Scope
1.1 This test method is intended for evaluating the resis- tance of pipe coating materials when exposed to various concentrations of reagents or suspected soil contaminants. The test serves as a guide to investigators wishing to compare the relative merits of pipe-coating materials in specific environ- ments. The choice of reagents, concentrations, duration of immersion, temperature of test, and properties to be reported are necessarily arbitrary and should be chosen to reflect conditions known to exist along the pipeline right-of-way. 1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only. 1.3 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. 1.4 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. Summary of Test Method
3.1 This test method consists of an immersion-type test in a closed container where coated pipe specimens are in long-term contact with both the liquid and vapor phase ofthe test reagent. Specimens exposed in this manner are inspected for visible signs of chemical attack. Subsequent tests for cathodic dis- bonding in accordance with Test Method G8, or penetration under load in accordance with Test Method G17, may be applied to determine if the specimens have undergone any loss of mechanical or bonding properties.
4. Significance and Use
4.1 The data obtained for short-term tests are of interest only in eliminating the most unsuitable materials or for indicating a probable order of resistance in any particular media. 4.2 Test conditions should take into account the manner and duration of immersion, the reagent, the temperature of the system, the area exposed above and below the liquid level, and other performance factors selected for the particular test.
5. Apparatus
5.1 Thickness Gage, capable of measuring the coating thickness in the manner prescribed by Test Method G12. 5.2 Test Container—A transparent closed container, sized to completely encase the pipe specimen and large enough to provide adequate exposure to both the liquid and vapor states of reagent. N OTE 1—For example, a 2-L (2.0-qt) capacity, Mason-type jar with a 70-mm (2.75-in.) diameter neck has been found suitable for use with 2 in. pipe and is illustrated in Fig. 1. 5.2.1 To avoid pressure build-up within the test containers, the threaded cup shall be replaced with a solid-rubber stopper. A positive venting device, such as a water seal, shall be used when testing with volatile solvents at elevated temperatures.5.2.2 A separate container shall be used for each test specimen. 5.3 Oven or Constant-Temperature Room or Bath—To en- sure uniformity of test results, the test cells and specimen shall be maintained at the test temperature 65°C (9°F) over the duration of the test period. 5.4 Auxiliary Testing Devices—Supplemental equipment used to determine specific mechanical properties of specimens before and after immersion shall conform to the requirements prescribed in the applicable ASTM test method.