This specification covers the standard requirements for welded nickel-chromium-iron alloy (UNS N06600, UNS N06603, UNS N06025, and UNS N06045) boiler, heat exchanger, and condenser tubes for use in general corrosion resisting and low- or high-temperature services. Tube shall be made from flat-rolled alloy by an automatic welding process with no addition or filler metal and shall be furnished with the oxide removed. The material shall undergo cold working in either the weld metal only or both weld and base metal subsequent to welding and prior to final annealing. The tubes shall be subjected to flattening test to check for superficial ruptures resulting from surface imperfections, flange test, and one of the following nondestructive tests: hydrostatic or pneumatic (air underwater) for leak testing and eddy current or ultrasonic for electric testing. The material shall conform to the chemical composition limits for nickel, chromium, iron, manganese, carbon, copper, silicon, sulfur, aluminum, titanium, phosphorus, zirconium, yttrium, and cerium. Tensile strength, yield strength, and elongation shall also meet the mechanical property requirements.

1.1 This specification covers welded UNS N06600,2 N06601, N06603, N06025, N06045, UNS N06690, UNS N06693, and UNS N06699 alloy boiler, heat exchanger, and condenser tubes for general corrosion resisting and low or high-temperature service.

1.2 This specification covers tubes ¹/₈ to 5 in. (3.18 to 127 mm), inclusive, in outside diameter and 0.015 to 0.500 in. (0.38 to 12.70 mm), inclusive, in wall thickness. Table 2 of Specification B751 lists the dimensional requirements of these sizes. Tubes having other dimensions may be furnished provided such tubing complies with all other requirements of this specification.

1.3 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.

1.4 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 become familiar with all hazards including those identified in the appropriate Safety Data Sheet (SDS) for this product/material as provided by the manufacturer, to establish appropriate safety, health, and environmental practices, and determine the applicability of regulatory limitations prior to use.

1.5 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.