Steel pipe

Nucor Skyline has extensive experience in manufacturing pipe pile products for the North American steel foundations industry. Thanks to our strategically located manufacturing plants, we can meet the needs of any project, whether public or private, throughout the region.

Steel pipe offers mechanical and physical characteristics that make it one of the most versatile construction products available on the market. As a structural element, steel pipe remains unmatched compared to other alternative materials. The flexibility offered by its manufacturing process, quality control, and low production cost position steel pipe as the new form of steel in numerous industries.

Advantages of Nucor Skyline Steel Pipes

• Wide range of diameters, thicknesses, and lengths
  
  • ERW Straight Seam: From 2-3/8” to 24” outer diameter; up to 0.625” thickness
  • Spiralweld: Up to 120” outer diameter; 1” thickness
  • Rolled and welded: Up to 204” outer diameter; 2.25” thickness
  • Micropiles: 5.5” – 20” outer diameter; primary and secondary quality
• Custom lengths and thicknesses
• Custom manufacturing services
• Spiralweld pipe accepted by DOTs in seismically active areas
• In-house and Third-party testing capabilities
• Manufactured in the U.S.

Types of Steel Pipes

Nucor Skyline manufactures three types of steel pipes with similar physical and chemical properties. All of them are welded in accordance with the required specifications and are as strong as the base material.

Electric resistance welded (ERW)
straight seam pipe

ERW pipe is manufactured from steel coils, with weld seams running parallel to the pipe. The width of the coil matches the circumference of the pipe, which limits the diameters to 24 inches. Nevertheless, the manufacturing process is fast, making it ideal for large production series of sections with diameters of 24 inches or less.

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Spiralweld Pipe

Spiralweld pipe, like ERW pipe, is also made from steel coils. The difference lies in the fact that the coil is wound at an angle, so that the weld runs along the outside of the pipe describing a helix. This allows for much greater variation in terms of diameter and thickness compared to ERW pipes. Spiral-welded pipes are most frequently used for diameters between 24 and 120 inches, and for thicknesses of 1.0 inch or less.

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Rolled & Welded Pipe

The rolled and welded pipe is manufactured from plate sections that are rolled to form shells. The seam of each shell is welded and, subsequently, the individual shells are welded together to form the finished pipe. Rolled and welded pipe can be manufactured with diameters of up to 16 feet and thicknesses greater than 2.0 inches.

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Applications of Steel Pipes

Bearing Piles

Deep foundations are required when the surface soils do not have sufficient strength to support the loads coming from the structure. Pipe piles are commonly used in deep foundations and transfer the building loads to more resistant soil layers located at great depth underground. The loads are resisted through lateral friction and tip resistance. The pipes can be driven with the end open or closed, using tips or plates. If they are driven with plates, the pipes can subsequently be filled with concrete to increase the pile's strength. Generally, the money that would be spent on plates, reinforcing bars, and concrete would be better used by investing it in a larger and thicker pile. The diameter of pipe piles ranges from a few inches to several feet, and they can be easily spliced to create piles hundreds of feet long.

Caissons

Caissons are most often used in bridge applications, where it is necessary to drill the riverbed —below the water level— to lay the foundation for piles or the structure's piers. Generally, these caissons consist of large-diameter steel pipes, exceeding 10 feet (or more). The use of large-diameter steel pipes —rolled and welded— makes it possible to install these high-strength foundation systems.

Drilled Shaft Casing

The use of casing —either temporary or permanent— is often required during the construction of bored piles. This casing is used to keep the excavation open while the reinforcement cage and concrete are installed. The ability to inspect the bottom of the excavation, together with the elimination of any variation in the diameter of the finished bored pile, results in a final pile of substantially higher quality. In its "Standard Guidelines for the Design and Installation of Pile Foundations," the ASCE recommends applying a safety factor 38% higher than the structural capacity of bored piles constructed without casing, compared to those built with casing.

Combination Walls

Large-diameter pipes have high bending resistance and are frequently used in combined sheet pile walls. The combination of large-diameter tubular piles and steel sheet piles — a system often called *combi-walls*, Z-pipe walls, or king pile walls — constitutes a highly efficient system. As in other combined walls, the king pile carries most of the load, while the sheet pile transfers that load to the pipe and to the ground.

Structural Sections

The symmetry of the pipe gives it the same bending resistance in any direction, making it an excellent product for resisting buckling. The stress required to cause buckling in an element under axial load decreases as its length increases. The radius of gyration has the opposite effect, increasing the capacity of a section to resist buckling. W and HP type sections have different radii of gyration (rx and ry) for the X and Y axes, while in the case of a pipe, this value remains constant. The end result is that a pipe can withstand considerably higher loads over long unsupported spans.

Threaded Micropile Casing

Micropiles are drilled and cast-in-place piles of small diameter, in which most of the applied load is resisted by a steel reinforcement. They are constructed by drilling a borehole—often using casing—followed by the placement of the steel reinforcement and the subsequent injection of the hole. Micropiles have a wide range of applications and are becoming an increasingly common method for supporting and reinforcing foundations, seismic retrofitting, slope stabilization, and even earth retention. They are an ideal solution for complex sites where low levels of vibration or noise are required, or where access is limited—for example, due to reduced clearance—and drilling is difficult.

Sign Poles, Towers, & Transmission Lines

Sign poles and towers are designed to resist large bending loads at the base of the structure. The availability and wide variety of thicknesses in large diameter pipes allow designers to select the exact size needed to address their particular project. Likewise, the pipes can be supplied in long sections, are easy to splice, and easy to drive into hard ground. Reduction collars can facilitate the splicing of different diameters, making the design as efficient as possible.

MINING

Mining operations are carried out at great depths below the surface, under dangerous conditions. The personnel, equipment, and ventilation shafts are integral parts of the mine. Vertical pipe sections are often used for the construction of such shafts. The wide range of diameters and thicknesses available makes steel pipe the material of choice to meet the various requirements of the shafts. Some of these shafts reach hundreds—if not thousands—of feet in length; in such cases, the pipes can be supplied in sections with the ends prepared for joining. Likewise, reinforcement rings can be used to keep the pipe thicknesses to a minimum.

Jacked & Bored

The installation of underground services is often carried out with jacked and boring pipes. Sections of pipe are pushed through the ground using hydraulic jacks, either between excavations or beneath a raised section of terrain. Then, the next section of pipe is spliced to the previous one, and the driving continues. Once the jacking is completed, the interior of the pipe is cleaned in order to proceed with the installation of the services. This method allows the placement of utilities without the need for extensive excavations, which could cause disruptions in roads, railways, homes, and businesses.

Line pipe for sewer & waste water

Welded steel piping provides an effective method for transporting liquids, air, and gases. Steel piping is, pound for pound, stronger than any other type of pipe. Pipe can be designed to withstand both internal and external pressures for most applications. Welded steel piping offers numerous advantages, such as strength, economy, and ease of installation. Nucor Skyline is SPFA certified and manufactures pipes subjected to hydrostatic testing, with outside diameters ranging from 10-3/4" to 90". Our production process uses double submerged arc welding on both spiralweld and rolled and welded pipes. The lengths of pipes subjected to hydrostatic testing vary from 30 to 60 feet, with wall thicknesses from 0.250" to 2.0", and are manufactured according to one of the following industry standards: AWWA C200, ASTM A139, or ASTM A134.