API 5L specifies the manufacture of seamless and welded steel pipes in two product grades (PSL1 and PSL2) for pipelines used in the transportation of oil and gas. Material use in sour service applications.
API 5L line pipe can be comprehensively divided into two categories based on the assembly cycle of the pipe: uniform line and welded pipe. Welded pipe is generally made by bending flat plates and welding them together. You can find a longitudinal weld on it; the larger diameter ones are generally spiral welded. Seamless steel pipe is generally formed by molten steel being squeezed out through an annular slit and then stretched, so there is no weld.
The seamless structure of seamless API 5L pipe ensures the consistency of material properties throughout the pipe body, eliminating potential weak points or stress concentrations associated with welds. This uniform structure enhances the ability of the pipe to withstand high internal and external pressures and cyclic loading conditions.
Due to the absence of welds, seamless API 5L pipe is not susceptible to corrosion, which can be a potential entry point for corrosive agents. This feature is important in applications such as offshore or subsea applications where corrosion resistance is critical.
Welded API 5L pipe is generally more cost-effective than seamless pipe, making it suitable for applications where performance requirements are less stringent or where cost is an important consideration. However, it is important to note that welded pipe may have limitations in maximum allowable pressure, temperature, and corrosion resistance due to potential weaknesses introduced by the weld.
One of the main applications of seamless API 5L pipe is in high-pressure transportation systems, where these pipes operate under extreme conditions, including high internal pressures, temperature fluctuations, and exposure to corrosive environments. Whereas welded API 5L pipe is typically used in gathering and transportation systems, where oil and gas are transported over shorter distances and at relatively low pressures.
API 5L Seamless Line Pipe
