The whole production process adopts strict raw material quality control. Incoming steel bars and steel billets are fully inspected for chemical composition, mechanical properties and factory test certificates to meet standard specifications. Unqualified materials are rejected directly. After strict inspection, qualified raw materials are precisely cut into standard forging blanks according to the dimensional requirements of 90°/45° LR/SR elbows, providing qualified blanks for subsequent forging production.
2.Hot Forging & Shaping
The qualified blanks are heated to the standard forging temperature by industrial heating furnaces, and then integrally forged and formed by hydraulic forging machines. During the one-piece hot forging process, the bending radii of LR (long radius) and SR (short radius) are precisely controlled to complete the integral forming of 90° or 45° elbow bodies. The forged blanks feature dense structure, high overall strength and excellent pressure resistance. After forming, trimming treatment is carried out to remove flash, burrs and excess materials, ensuring regular workpiece outline and accurate benchmark size.
3.Heat Treatment & Surface Cleaning
According to different material grades and service requirements, all forged elbows undergo professional heat treatment processes including annealing, normalizing and quenching & tempering. The process thoroughly eliminates internal forging stress, stabilizes product performance, and improves mechanical toughness and pressure-bearing capacity. After heat treatment, shot blasting or sand blasting is applied to completely remove surface oxide scales and impurities, obtaining smooth and clean forging surfaces for subsequent precision machining.
4.Precision Machining & Thread Processing
The elbow end faces and inner holes are finished by precision machining to ensure flatness and dimensional accuracy. The internal thread processing strictly complies with ASME B1.20.1 and relevant industry standards, supporting customized processing of NPT, BSPT, BSPP and other standard threads. All thread tolerances, wall thickness and bending dimensions are precisely controlled to guarantee precise assembly, reliable sealing and convenient disassembly of pipeline systems.
5.Strict Testing & Marking
All finished elbows pass comprehensive dimensional inspection covering bending radius, wall thickness, overall dimension and thread specification. For high-pressure industrial and engineering applications, optional non-destructive testing such as UT, MPI and PT is available to eliminate internal and surface potential defects. Qualified products are permanently stamped with company logo, material grade, heat number, pressure class and execution standard to realize full product traceability.
6.Surface Treatment & Finished Packaging
According to customer demands and service environments, finished products are processed with anti-rust and anti-corrosion treatments including black oxide, hot-dip galvanization and anti-rust oil coating. After strict final visual inspection to exclude cracks, thread damage and appearance defects, qualified products are packed in standard plywood cases or wooden crates. The professional packaging effectively prevents collision and corrosion during long-distance sea transportation and ensures intact product delivery.