Seamless Steel Tee Factory

 Seamless Steel Tee Factory
Hebei Longrun Pipeline Group Company operates a comprehensive production facility dedicated to the manufacture of seamless steel tees. These components play a vital role in piping networks across industries such as oil and gas, petrochemicals, power generation, and water treatment. By integrating advanced metallurgy with precision engineering, our factory ensures each seamless tee meets rigorous demands for dimensional accuracy, mechanical strength, and corrosion resistance.

Material Selection and Metallurgical Foundations
The process begins with selecting high-grade alloy steels—commonly carbon steel, low-alloy steel, or stainless steel grades—sourced from reputable steel mills. Each batch undergoes chemical composition analysis to verify elements such as carbon, manganese, sulfur, and phosphorus content. Maintaining strict chemical tolerances is essential for ensuring weld integrity and long-term performance in high-pressure applications.

Following chemical validation, the steel billets are subjected to ultrasonic or magnetic particle inspection to detect any internal defects, such as cracks or inclusions. Only billets that pass nondestructive testing proceed to the forging stage, safeguarding the final product against failures in field service.

Forging and Forming Processes
Seamless tees are formed through a hot forging process. Billets are heated in controlled-atmosphere furnaces to temperatures typically between 1150 °C and 1250 °C. This thermal treatment softens the metal, enabling uniform deformation. The billets are then pierced to create a hollow shell, followed by shaping on a mandrel or a hydraulic press to generate the tee geometry.

Our facility employs both hydraulic and mechanical forging presses, each chosen for its precision control over speed, pressure, and dwell time. The two main forming methods—hot extrusion and hot pressing—offer flexibility in producing large diameters or specialized wall thicknesses. Skilled technicians monitor forming parameters to maintain wall thickness tolerance within ±10% of nominal specifications.

Heat Treatment and Mechanical Properties
After forging, the tees undergo heat treatment to refine the microstructure and enhance mechanical properties. The typical regimen involves quenching and tempering: rapid cooling in oil or water, followed by reheating to a tempering temperature that balances hardness and toughness. This heat treatment cycle ensures the seamless tees achieve yield strengths exceeding 235 MPa (for grade ASTM A420 WPL6) and impact toughness values suitable for low-temperature service.

Post-heat-treatment, samples from each heat lot are tested in our in-house laboratory. Tensile tests confirm ultimate tensile strength and elongation meet or surpass ASTM standards. Charpy V-notch impact tests validate performance under sudden loading or temperature fluctuations.

Precision Machining and Surface Finishing
To meet stringent dimensional requirements, each tee is machined on CNC lathes and milling centers. Machining operations produce accurate branch angles, flange faces (if specified), and sealing surfaces. Wall thickness uniformity is verified using ultrasonic thickness gauges, ensuring consistency even in complex geometries.

Surface treatment follows machining, tailored to client specifications and service environments. Options include pickling and passivation for stainless grades, shot blasting for carbon steel, and application of primer coatings such as epoxy or zinc-rich paints. For subsea or highly corrosive applications, the tees can receive fusion-bonded epoxy or polyurethane coatings.

Quality Assurance and Certification
Quality management at Hebei Longrun Pipeline Group Company adheres to ISO 9001:2015 standards. A dedicated quality control team oversees document reviews, in-process inspections, and final examinations. Inspection reports accompany each shipment, detailing dimensional reports, material certificates (EN 10204 3.1 or 3.2), and nondestructive testing records.

Third-party certification is available upon request, including approvals from LR, DNV, ABS, and other classification societies. This ensures seamless integration of the tees into offshore or marine projects where independent verification is mandatory.

Applications and Market Deployment
Seamless steel tees fabricated at our factory are deployed in:

Oil & Gas Pipelines: Branching lines in high-pressure transport, subsea manifolds, and wellhead assemblies.

Petrochemical Plants: Process piping for reactors, heat exchangers, and distillation columns, where high-temperature resilience is critical.

Power Generation: Steam and water distribution in nuclear, coal‐fired, and gas turbine plants.

Water Treatment: Networks requiring corrosion-resistant fittings in desalination plants and sewage treatment facilities.

Our production capacity and logistical infrastructure support both domestic and international projects, with the ability to handle bespoke orders, including oversized tees (up to 1,200 mm diameter) and specialized alloys for sour-service environments.