ASTM A335 P91 Large Diameter Boiler Pipe from China
Seamless Grade P91 chrome-moly alloy steel pipe for elevated-temperature service in refining furnaces and supercritical boilers, with 508 mm OD. It provides excellent creep resistance for high-pressure feedwater heaters. Falls under 7304.59.20.80 as other alloy steel seamless tubes over 406.4 mm OD suitable for boilers and refining furnaces.
Duty Rate — China → United States
35%
Rate breakdown
9903.03.0110%Except for products described in headings 9903.03.02–9903.03.11, articles the product of any country, as provided for in subdivision (aa) of U.S. note 2 to this subchapter
9903.91.0125%Effective with respect to entries on or after September 27, 2024, articles the product of China, as provided for in subdivision (b) of U.S. note 31 to this subchapter
Import Tips
• Provide hydrotest and nondestructive electric test (NDT) certificates as required for P91 grade to prove pressure integrity
• Declare exact alloy elements (9% Cr, 1% Mo) in entry docs; mismatches lead to duty reassessment or penalties
• Avoid bundling with fittings; ship as individual lengths to prevent set classification under 7307 or 7308