ASME SA333-6 Buried Line Pipe

ASME SA333 Grade 6 Buried Line Pipe is a low-temperature carbon steel seamless pipe engineered for underground pipeline applications in cold and high-pressure environments. Manufactured to meet the rigorous requirements of the ASME SA333 specification, Grade 6 pipes are known for their superior impact toughness, structural integrity, and resistance to brittle fracture—making them an ideal choice for buried transmission lines carrying oil, gas, water, or other fluids.

This pipe is produced using a seamless process, ensuring a consistent wall thickness and eliminating weld seams that could become weak points under pressure or corrosion. SA333 GR.6 is especially suitable for buried pipeline systems installed in regions with harsh winters or permafrost, where resistance to cracking at sub-zero temperatures is critical.

With a balanced composition of carbon, manganese, phosphorus, sulfur, and silicon, ASME SA333 Grade 6 offers excellent weldability, ductility, and mechanical strength. It is typically supplied in a normalized or normalized and tempered condition to enhance grain refinement and improve low-temperature performance.

Mechanical properties include:

Minimum yield strength: 240 MPa (35,000 psi)

Minimum tensile strength: 415 MPa (60,000 psi)

Excellent notch toughness at -45°C (-50°F)

High elongation and resistance to impact loading

Typical applications:

Underground oil and gas transmission pipelines

Low-temperature buried water lines

Cryogenic and LNG distribution networks

Petrochemical and refinery pipeline infrastructure

Industrial pipeline systems in cold regions

Available in a wide range of outer diameters (typically 1/2" to 36") and wall thicknesses (standard and heavy schedules), ASME SA333-6 pipes can be customized to meet specific project conditions. Pipe ends may be supplied as plain ends (PE), beveled ends (BE), or threaded ends (TE) as needed for welding or mechanical connection.

Each pipe undergoes rigorous quality inspection, including hydrostatic testing, Charpy V-notch impact testing at low temperatures, ultrasonic and radiographic inspection, and full chemical analysis. Third-party inspections and certifications (SGS, BV, TUV, etc.) are available to ensure compliance with industry standards and project specifications.

In summary, ASME SA333 Grade 6 Buried Line Pipe is a robust, reliable solution for underground pipeline systems operating in cold and high-pressure environments. Its seamless construction, proven low-temperature performance, and compliance with ASME standards make it a trusted material for modern buried infrastructure around the world.