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Calcium Silicate Boiler Wall Insulation Blocks from China

Dense molded blocks used to line high-pressure boiler walls, offering superior thermal stability and fire resistance from calcium silicate composition. Falls under HTS 6806.90.00.20 as 'other' heat-insulating articles of molded calcium silicate mineral material.

Duty Rate — China → United States

37.5%

Rate breakdown

9903.88.0325%Except as provided in headings 9903.88.13, 9903.88.18, 9903.88.33, 9903.88.34, 9903.88.35, 9903.88.36, 9903.88.37, 9903.88.38, 9903.88.40, 9903.88.41, 9903.88.43, 9903.88.45, 9903.88.46, 9903.88.48, 9903.88.56, 9903.88.64, 9903.88.66, 9903.88.67, 9903.88.68, or 9903.88.69, articles the product of China, as provided for in U.S. note 20(e) to this subchapter and as provided for in the subheadings enumerated in U.S. note 20(f)
9903.05.3112.5%Section 301 (forced labor) — additional 12.5% ad valorem on products of China

Import Tips

Provide engineering drawings showing molded shape and end-use in power plants to support classification

Ensure no organic binders are present, as they could trigger reclassification to composite materials

Watch for undervaluation penalties; use transaction value based on comparable industrial sales