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Hebei Longrun Pipeline Group Company is an API certified 180° elbow manufacturer supplying return bends for oil and gas transmission, refinery piping systems, and industrial process pipelines. A 180° elbow, also known as a return bend, redirects fluid flow back in the opposite direction and is commonly used in compact piping layouts and heat exchange systems.
A 180° elbow differs from standard 90° or 45° elbows in its geometry and structural demands. The continuous curvature requires precise control over bending radius and wall thickness to prevent thinning at the outer arc or excessive thickening at the inner arc.
Typical radius configurations include:
Long radius (LR): 1.5D
Short radius (SR): 1D
Custom radii for specific design requirements
The choice of radius directly affects flow characteristics, pressure drop, and mechanical stress distribution within the pipeline system.
As an API certified manufacturer, Hebei Longrun Pipeline Group Company operates under controlled quality management procedures that align with API requirements for material control, production processes, inspection, and documentation. API compliance is particularly important for oilfield and energy sector projects where standardized quality assurance is mandatory.
Each 180° elbow is produced using materials that meet specified chemical and mechanical criteria. Material certificates and traceability documentation accompany every batch to ensure transparency throughout the supply chain.
API certified 180° elbows are typically produced using one of the following methods:
Hot Induction Bending: Suitable for larger diameters and thicker walls. The pipe is heated and gradually bent to achieve a smooth 180° curve with controlled deformation.
Hot Push Forming: Common for seamless elbows. A heated pipe is pushed over a specially designed die to form a uniform return bend.
Welded Fabrication: For large-diameter or custom applications, segments may be welded and subsequently heat-treated to restore mechanical properties.
Throughout production, dimensional accuracy is monitored to maintain required tolerances for outside diameter, wall thickness, center-to-center distance, and end preparation.
After forming, heat treatment such as normalizing or quenching and tempering is applied to restore uniform mechanical properties. This step reduces residual stress and enhances toughness, especially for low-temperature or high-pressure service.
Inspection procedures include:
Visual and dimensional inspection
Ultrasonic testing for internal flaws
Radiographic testing for welded sections
Hardness and tensile testing
Impact testing when required
Additional third-party inspection can be arranged according to project specifications.
Standard end preparation includes beveling for butt-weld connections in accordance with piping codes. Surface treatment may include shot blasting and temporary anti-rust coating. Markings indicate size, schedule, material grade, heat number, standard reference, and manufacturer identification to ensure full traceability.
API certified 180° elbows from Hebei Longrun Pipeline Group Company are commonly installed in:
Oil and gas gathering and transmission systems
Refinery return lines and process loops
Heat exchanger piping
Compressor and pump discharge systems
Offshore production platforms
By combining controlled forming processes, documented quality systems, and API compliance, our 180° elbows are manufactured to meet the operational and regulatory requirements of modern energy and industrial pipeline projects.
