L360 Seamless Steel Pipe for Natural Gas with 3LPE Polyethylene Anti-corrosion Coating

In the field of natural gas transportation, L360 seamless steel pipe, with its high strength and low alloy content, has become a key material for ensuring the safe and stable operation of pipelines. The addition of 3LPE polyethylene anti-corrosion technology further enhances its superior durability and reliability in harsh environments.

L360 seamless steel pipe is specifically designed for high-pressure transportation scenarios such as oil and natural gas. Its yield strength is not less than 360MPa, and its tensile strength can reach 460-760MPa, enabling it to withstand external forces under complex geological conditions. L360 seamless steel pipe conforms to GB/T9711 PSL2 standard and is delivered through normalized rolling or normalized and tempered processes to ensure uniform material structure and stable performance. The chemical composition of L360 seamless steel pipe is strictly proportioned, with a carbon content of ≤0.24% and a manganese content of ≤1.4%, and the addition of microalloying elements such as vanadium and niobium, which improves weldability and resistance to hydrogen-induced cracking while ensuring strength, providing a safe foundation for natural gas transportation.

The L360 seamless steel pipe's external 3LPE anti-corrosion coating employs a three-layer composite structure: the bottom layer is fusion-bonded epoxy powder (FBE), providing excellent interfacial adhesion and chemical corrosion resistance; the middle layer is an adhesive, ensuring a tight bond between the epoxy and polyethylene layers; and the outer layer is high-density polyethylene (PE), 2.5-3.7 mm thick, forming a dense mechanical protective barrier. This structure of the L360 seamless steel pipe combines the chemical resistance of the epoxy coating with the impact resistance of polyethylene, ensuring the anti-corrosion layer remains stable within a temperature range of -60℃ to 60℃, with a water absorption rate of less than 0.01%, effectively resisting soil stress, chemical corrosion, and mechanical damage.

The combination of L360 seamless steel pipe and 3LPE anti-corrosion technology has been widely applied in key national projects such as the Shaanxi-Beijing natural gas pipeline and the West-East Gas Pipeline. Practice has shown that this anti-corrosion system can extend the service life of buried pipelines to over 50 years, significantly reducing the total life cycle cost. Its construction technology is mature and can be achieved through two methods: winding or circular mold wrapping. It also has high bonding strength with steel pipes and no risk of leakage.