API 5L X42 PSL1 welded steel pipe, with its balanced mechanical properties and optimized manufacturing process, demonstrates excellent efficiency and durability in the energy transmission field. As a basic steel grade product under the American Petroleum Institute (API) standard, X42 PSL1 has a yield strength of 290 MPa and a tensile strength range of 415-655 MPa. Combined with the strict control of chemical composition (carbon equivalent ≤0.25%) of the PSL1 grade, it can maintain a Charpy impact energy of over 27 J even at -20℃, meeting the typical operating conditions of low- and medium-pressure natural gas transmission in Class II and Class III onshore areas.
X42 welded steel pipe adopts high-frequency resistance welding (ERW) technology, achieving instantaneous metal fusion through a high-frequency current of 150-400 kHz. Coupled with a dual monitoring system of online eddy current detection and ultrasonic flaw detection, the defect detection rate reaches 99.97%, ensuring stable weld quality. During production, medium-frequency induction heating technology precisely controls the weld zone temperature at 50-80℃ above the Ac3 phase transformation point, effectively eliminating residual welding stress. Combined with a fully automated control unit (production speed up to 40 meters/minute), the welded steel pipe wall thickness tolerance is controlled within ±0.15mm, offering superior dimensional accuracy compared to traditional seamless steel pipes and significantly reducing on-site installation and connection difficulties.
Regarding corrosion protection, the adhesion test of the three-layer PE coating (epoxy primer + adhesive + polyethylene topcoat) reaches ≥50N/cm. Combined with micro-alloying design (adding Nb, V, and Ti elements to achieve fine-grained strengthening), the welded steel pipe has a service life exceeding 30 years in acidic and alkaline soil environments. In practical applications, the X42 PSL1 welded steel pipe set a record for continuous laying of a single steel pipe section of 38 kilometers in the West-East Gas Pipeline III branch line project. Its “weld-then-bend” process supports cold bending of a minimum pipe diameter of 18 times, reducing the number of joints in mountainous areas by up to 40% and improving overall construction efficiency by over 25%.
From an economic perspective, the unit length cost of this grade of welded steel pipe is 15%-20% lower than that of seamless steel pipe, and the maintenance cycle of the 3PE anti-corrosion coating is extended to more than 15 years, resulting in a significant cost advantage over the entire life cycle. With the continued growth in global demand for energy pipeline construction, API 5L X42 PSL1 welded steel pipe has become the preferred material for medium and low-pressure long-distance pipelines.
Post time: Nov-05-2025