API 5L X42 Buried Line Pipe

API 5L X42 Buried Line Pipe is a high-strength carbon steel pipe designed for the underground transportation of oil, natural gas, water, and other fluids in pressurized pipeline systems. Manufactured in accordance with the API 5L standard, X42 indicates a minimum yield strength of 42,000 psi (290 MPa), offering a balance between durability, flexibility, and cost-effectiveness—ideal for buried pipeline applications where reliability and long service life are critical.

This pipe is available in both seamless and welded forms, with seamless pipes offering greater resistance to internal pressure and structural stress. When used as buried line pipe, API 5L X42 is typically coated with external anti-corrosion layers such as FBE (Fusion Bonded Epoxy), 3LPE, or coal tar enamel to protect against soil moisture, electrochemical reactions, and mechanical abrasion.

The steel used in API 5L X42 has a carefully controlled chemical composition that includes carbon, manganese, phosphorus, sulfur, and silicon, along with optional microalloying elements. This ensures good mechanical strength, excellent weldability, and the ability to withstand the thermal expansion and ground movement that underground pipelines often experience.

Mechanical properties include:

Minimum yield strength: 290 MPa (42,000 psi)

Minimum tensile strength: 415–760 MPa (60,000–110,000 psi)

Good elongation, impact resistance, and ductility

Suitable for sour and sweet service environments

Typical applications include:

Underground oil and natural gas transmission lines

Water distribution and injection systems

Gas gathering networks in remote or harsh environments

Petrochemical and utility piping buried below ground

Structural piping for long-distance pipeline infrastructure

API 5L X42 Buried Line Pipe is available in sizes ranging from 1/2 inch to 48 inches in diameter, with wall thicknesses according to standard schedules (SCH40, SCH80, SCH160) or custom requirements. Pipe ends can be delivered plain, beveled, or threaded, and the product can be supplied in random, fixed, or double random lengths depending on the project needs.

Pipes are subject to strict quality control, including hydrostatic testing, ultrasonic or radiographic inspection, Charpy impact testing (when required), dimensional checks, and full chemical analysis. All products meet the requirements of API 5L PSL1 or PSL2, depending on the specified service conditions. Third-party inspection reports and certificates (SGS, TUV, BV) are available upon request.

In summary, API 5L X42 Buried Line Pipe is a robust, corrosion-resistant solution for underground fluid transport. Its high strength, adaptability to harsh soil conditions, and compliance with international pipeline standards make it a reliable choice for long-term, high-efficiency infrastructure in the oil, gas, and water industries.