ASME B16.9 UNS S32750 Lap Joint Stub Ends are commonly used in piping systems in conjunction with loose flanges to facilitate the connection and disconnection of pipelines. HT PIPE is a leading stockist and global exporter with over 15 years of expertise in international trade. We supply pipes, plates, round bars, and a comprehensive range of pipe fittings, flanges, and valves. Contact us now for free quotes and personalized product information.
S32750 Material Characteristics
Corrosion Resistance: Resistance to pitting and crevice corrosion, capable of withstanding corrosive media such as seawater, acidic oil and gas, and chloride solutions, suitable for harsh corrosive environments.
Mechanical Properties: Tensile strength ≥ 795 MPa, yield strength ≥ 550 MPa, higher strength than 304 and 316L stainless steel, allowing for reduced pipe wall thickness and lower system weight.
Temperature Adaptability: Long-term operating temperature range of -50℃ to 300℃, meeting the needs of low-temperature and medium-temperature process pipelines.
2507 Dual-End Functional Differentiation
One end is the welding end: Connected to the main pipe body using butt welding or socket welding, requiring matching with the pipe's outer diameter and wall thickness to ensure welding strength.
The other end is the flanged end: Extending radially outward to form an annular flange (lap joint), the outer diameter and thickness of which must precisely match the groove dimensions of the loose flange. The mating surface between the groove and the flange serves as an auxiliary sealing surface.
ASME B16.9 S32750 Lap Joint Stub Ends Welding Process Key Points
Welding Material Selection: A special welding material matching the chemical composition of the base metal must be selected to maintain an appropriate nitrogen content and duplex structure in the weld metal. Commonly used welding wire is ER2594, and welding rod is E2594.
Welding Protection: During welding, the back of the weld seam needs to be protected with argon to ensure that the oxygen content is below 0.05% (or 500 ppm) to prevent root oxidation.
Heat Input and Interpass Temperature Control: Welding heat input and interpass temperature must be strictly controlled (typically recommended to be ≤100°C) to avoid prolonged exposure to the 475°C embrittlement temperature range and prevent the precipitation of harmful intermetallic phases.
Cleaning Requirements: The welding area must be thoroughly cleaned to remove grease, moisture, and impurities. Special tools should be used during the process to strictly prevent carbon steel contamination and iron ion contamination, which could impair corrosion resistance.
