Carbon Steel Elbows Factory

Carbon Steel Elbows Factory
Hebei Longrun Pipeline Group Company’s carbon steel elbows factory specializes in manufacturing seamless and welded elbows designed to change piping direction with precision and reliability. These fittings are essential across diverse industries, providing fluid redirection in systems handling pressures from 0.6 MPa to 32 MPa and temperatures ranging from –29 °C to 400 °C.

Raw Material Procurement and Inspection
Our factory sources carbon steel grades compliant with ASTM A234 WPB, ASTM A420 WPL6, and other recognized standards. Steel pipes and bars undergo rigorous entry inspections, including dimension checks, ultrasonic flaw detection, and verification of mill certificates. These measures ensure base materials are free from voids, cracks, or foreign inclusions.

Elbow Forming Techniques
We employ two principal forming methods:

Hot Induction Bending

A section of straight pipe is heated by an induction coil to the target deformation temperature.

Bending machines clamp and shape the heated segment around a mandrel, controlling radius-to-diameter ratios (e.g., 1D, 1.5D, 3D, 5D).

This method produces smooth curvature without welding, preserving material integrity and uniform wall thickness.

Cold Bending with Mandrel Support

Room-temperature bending using mechanical presses and segmented mandrels.

Ideal for large-diameter or thick-walled elbows where heat input must be minimized.

Secondary heat treatment may follow to relieve residual stresses.

For smaller-diameter elbows (≤β 219 mm), centrifugal casting and cold forming followed by heat treatment are also available, offering cost-effective solutions for standard fittings.

Heat Treatment and Mechanical Testing
After shaping, elbows undergo normalizing or quenching and tempering based on material grade:

Normalizing: Heating to 880–920 °C and air cooling to refine grain structure.

Quenching & Tempering: Rapid cooling in water or oil, followed by tempering at 580–650 °C, yielding a balance of strength and ductility.

Mechanical testing—tensile, hardness, and impact—verifies compliance with ASTM or EN requirements. Hydrostatic tests at pressures 1.5 times the design pressure confirm the absence of leaks or deformation.

Finishing Processes
Our factory offers a range of finishing options:

Beveling: Standard 30°±5° bevels for butt-weld applications.

Shot Blasting: Surface cleaning to SA 2.5 standard, preparing for coatings.

Painting & Coating: Primers and topcoats selected for environmental exposure—epoxy, coal tar epoxy, or fusion-bonded coatings.

Threading: NPT or BSP threads available for low-pressure applications.

Custom marking—stenciled or stamped—with batch number, heat code, and size ensures traceability throughout the supply chain.

Quality Control and Compliance
An integrated quality control system monitors each stage:

In-Process Inspection: Dimensional verifications using laser scanners and micrometers.

Final Inspection: Visual checks, third-party witness testing, and documentation review.

Certification: Material test certificates (EN 10204 3.1), NDT reports (RT, UT, PT), and compliance certificates for PED, ASME B16.9, or GB standards.

These measures align with our commitment to meeting customer specifications without reliance on promotional language, focusing purely on technical excellence and reliability.

Service Range and Industry Applications
Carbon steel elbows from Hebei Longrun Pipeline Group Company serve in:

Refinery Piping: Fuel lines, crude units, and hydrocracker systems requiring high-pressure elbows.

Chemical Plants: Process lines handling corrosive fluids and high temperatures.

HVAC and Plumbing: Water, steam, and gas distribution networks in commercial and industrial buildings.

Shipbuilding and Offshore: Hydraulic, fire-fighting, and ballast systems where robustness is critical.

With a production capacity exceeding 10,000 tonnes per month, our factory can accommodate standard and bespoke orders, delivering finished elbows within competitive lead times. We provide end-to-end support—from technical inquiry and material selection to delivery—ensuring seamless integration into client projects.