D6137-97 – Standard Test Method Technical Guide

📚 Scope and Significance

This test method, D6137‑97 (Reapproved 2018), under the jurisdiction of ASTM Committee D33, evaluates the sulfuric acid resistance at elevated temperatures of polymer linings on carbon steel substrates for flue gas desulfurization (FGD) systems. The values stated in inch‑pound units are standard, with SI units provided for reference. The test assesses the combined effects of heat and acid exposure, focusing on major failure modes such as blistering, cracking, checking, and flaking. It is intended for use in selecting linings for surfaces exposed to hot unscrubbed flue gas or reheated scrubbed gas above the water dew point. This method does not evaluate thermal gradients through the lining or conditions at or below the water dew point.

🛠️ Test Setup and Procedure

Square test panels coated with the lining system are cycled from room temperature to a designated elevated temperature. Substrates conforming to A36/A36M carbon steel are prepared by SSPC SP5 white metal blast cleaning, with surface profile measured per D4417. Coating thickness is determined using D4138 (destructive) or D1186 (non‑destructive). The test does not simulate the thermal gradient of field applications. It excludes concurrent physical or mechanical effects and other chemicals in flue gas, which may affect actual performance.

📊 Evaluation and Reporting

After exposure, the lining is evaluated for defects using standard test methods from ASTM and SSPC. Key evaluation standards include D714 for blistering, D661 for cracking, D660 for checking, and D772 for flaking. Additional testing may involve holiday detection per D5162 and indentation hardness per D1474. Results are reported in combination with other test data for comprehensive lining selection.

© 2026 TNLab — This article is a technical interpretation for reference only. The original standard as published by ASTM International takes precedence.