To start the steel manufacturing process, we bring in the raw material, which would be steel coil. That coil is going to be loaded onto the mill, it’s going to be fed into the forming section of the mill, and that’s where the spiral welding will occur and manufacture the pipe.
Once the coil is loaded on the end of the mill, it’s going to be fed into the mill where we’re going to start to flatten it. It’s going to go through a series of rolls trying to flatten and also maintain straightness as is presented into the forming section.
Then it’s going to hit the driver, which is the main part of the mill that’s pulling the coil in one side and pushing it into the forming section. And after the driver is where the beveling operation occurs.
Once it’s into the forming section, it’s also coming around and getting that first initial inside diameter weld. During that phase, we’re actually welding the ID and the OD to accomplish a complete joint penetration weld, the CJP weld, in that area.
Once the ID weld is accomplished, the pipe is going to rotate around a couple times and then the OD weld will be complete, making that CJP joint.
The weld process is what we call SAW, submerged arc welding, and it’s where the weld occurs under a mantle of flux. It’s a very efficient process, and it’s very and it’s also very automated, which allows us to be very consistent with the welding of the pipe.
The spiral pipe manufacturing process is continuous, and in theory the pipe made off the mill can be infinite length. However, we can specify a specific length and the machine can cut pipe to a specified length.
We use a plasma torch set per the project requirement length of pipe, and that’s going to create a cut while the pipe is actually being formed. That cutting mechanism is going to translate with the pipe that’s being made, so you have a nice clean circumferential cut to the desired length.
On the quality side, we want to be sure that the SAW weld is performed as we expect.
On an incremental basis, we’re going to perform destructive testing on that weld. And those are called weld production tests. We’re going to do that at the beginning of a run where we validate that the weld that we desire is being accomplished, we’re going to do that at certain intervals throughout the manufacturing process, and then we’re going to do that on the tail end as well. That way we can have bracketed areas where we have validated the weld through a weld production test.
Once the pipe is cut from the mill at the specified length, it’s going to be transferred to an inspection station and ultimately a staging area where it’ll be staged until we’re ready for bell expansion.
