Strong Connections in OCTG

In the first two articles in this series, we related how SMW Autoblok revolutionized the OCTG industry with it’s innovative self-centering technology and how to align large diameter oil county pipe on center.

DSC00658[2]-mit Muffe_croppedBut one serious problem remained. One section of pipe is about 40’ long and pipelines have to go on for miles. How do you join sections of tubing together with joints that have the strength and integrity of the pipe itself? As outlined in our last article, you could thread the pipe and link it end to end, but this is cost prohibitive and is best used for specialized applications. That’s why the most common way of joining pipe in oil fields today is coupling.

Simply put, a coupler is a two-sided device that connects two pieces of pipe together. It is less expensive than Integral joint connection and just as strong; however, threads have to be timed perfectly to each other (equal on both sides) to prevent leaks or bursting. And by equal, we mean exact.

The Old Way: Labor Extensive and Error-Prone
Originally, machining a coupler took more than six steps. An operator would machine one side of the coupler on a lathe, open the door, take the workpiece out, index it by hand, put it back in the lathe, close the door and then machine the second side.

Not only does this extend the cycle time, but critical workpiece positioning references (also called clocking) can be lost in the manual process. These need to remain constant throughout the machining process in order to make an accurate part. This potential for error could result in a faulty coupler, meaning leaks or broken pipes in the field.

Breaches in an underground pipeline are unacceptable, both financially and environmentally. Our engineers set out to find a better way to machine couplers and mitigate that risk.

SF RAZ2G chuck indexing_editedThe New Way: Clamp Once, Machine Twice
The results of our R & D efforts was the SF-RAZ2G two position hydraulic ring indexing chuck – the first workholding specifically designed for the machining of couplings in one set up.

The SF-RAZ2G clamps the coupling on the outside diameter so the thread can be machined on the first side, then it hydraulically rotates the coupling 180° on the centerline so the other side can be threaded. The coupling does not have to be reoriented for the second threading – the clocking is a perfect match.

Accuracy and Speed 
The SF-RAZ2G distributes the clamping forces over six jaws to prevent deviation from roundness or other distortion. The indexing process takes mere seconds and eliminates the time it takes to open the door, manually reorient the part, close the door and hit cycle start. If you do the math, it’s quite a time saver over the course of a year.

In addition, since the workpiece is held so securely by the SF-RAZ2G, the cutting tool speeds and feeds can be increased, taking even more time out of the process. If you want to take another step and add machine tending robotics, the SF-RAZ2G comes automation-ready.

The Pipeline is a Lifeline
Our contributions to OCTG, as outlined in this series of articles, have a direct impact on the average consumer. Every drop of oil that makes it safely from the pump to the refining plant helps keep oil prices down. That is good for the oil companies, our economy and our planet.

If you would like to discuss your workholding requirements in oil country or anywhere in the United States, please contact us.