ASTM D6137-97(2018)

3.1 The results obtained by this test method can be used in combination with other test methods for the selection of a lining for surfaces in flue gas desulfurization (FGD) systems that will be exposed to hot unscrubbed flue gas or to scrubbed gas that has been reheated well above the water dew point.

3.2 This test method is intended to evaluate the combined effects of heat and exposure to sulfuric acid upon a lining system as applied to a carbon steel substrate. It does not produce the thermal gradient through the lining that may exist in actual applications. Actual lining performance may also be affected by concurrent physical or mechanical effects and other chemicals that may be present in the flue gas.

3.3 This test method evaluates major failure modes of linings applied to square test panels that are cycled from room temperature to a designated elevated temperature.

3.4 The recommended test temperatures of 200°F (93°C) and 350°F (177°C) are based on typical maximum operating zone temperatures in flue gas desulfurizations systems. Other temperatures may be evaluated as desired. Cycling to lower temperatures, including freezing, may be considered if applicable.

3.5 The standard acid concentration for all tests is 20 %, recognizing that the concentration will quickly rise to the equilibrium at the selected test temperature.

1.1 This test method is intended to evaluate the sulfuric acid resistance at elevated temperatures of polymer linings applied to carbon steel substrates subject to sulfuric acid attack.

1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.

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 appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.