Skyline - Steel Sprial Weld Pipe

• Spiralweld: Up to 120” OD; 1” Thickness
• Custom Lengths and Thicknesses
• Custom Fabrication Services
• Accepted by DOTs in Seismically Active Areas
• In-house and Third-Party Testing Capabilities
• Made in the USA

Spiralweld pipe, like ERW, is also manufactured from steel coil. The difference is the coil is wound at an angle, so the weld runs around the outside of the pipe in the shape of a helix. This allows for a lot more variation in diameter and thickness than ERW pipe. Spiralweld pipe is most commonly used for pipe diameters between 24 in. and 120 in. and for thicknesses of 1.0 in. or less.

Manufacturing Process

The spiralweld manufacturing process is one of the most cost effective ways to produce steel pipe. Spiralweld pipe is manufactured from steel coil and typically utilizes a helical double submerged arc weld (DSAW). The mill setup offers avarying degree of flexibility, allowing for production of a wide range of pipe diameters and wall thicknesses. As a result,Nucor Skyline is able to offer spiralweld products for structural and non-structural applications.

UNCOILING

Upon receipt of the coil, it is placed on a horizontal uncoiler mandrel and fed into the straightener.
  
Flattening
The strip of coil is introduced into the flattener through a roll stand and the coil set is removed.
   
Joining Coil ends
As the coil continues to move through the straightener, the leading and trailing edges of the strip are trimmed in preparation for butt welding – coil to coil.
   
EDGE MILLING
The edges of the coil are trimmed with carbide teeth to prepare for welding.

PIPE SPIRALING

The strip of coil enters the three roll apparatus composed of lead, buttress and mandrel roll sets. At this stage, the coil starts to form the spiral shape that will then become pipe.

PIPE WELDING

The welding system welds the pipe, first along the inside diameter and then along the outside diameter, using a submerged arc welding process.

QUALITY CONTROL

Once the welding is complete, the finished pipe is visually inspected by Quality Control (QC) and, if required, Ultrasonic (UT) testing is performed to ensure the weld is defect-free.

PIPE CUT-OFF

Once the pipe reaches the desired length, the cut-off machine is engaged. Traveling with the pipe, a plasma torch provides the cut-off of the finished pipe. Specific end props, such as bevel or square cut ends, can be requested to allow for simpler splicing in the field.