One benefit of continuous weld (CW) pipe is its easy threadability in the field, compared to ERW (electric resistance welded) pipe. Today we want to explore this benefit of CW pipe by discussing the threading process and highlighting additional CW benefits.
This process requires a universal die head, which threads pipe from 1/8" to 2" in diameter. Lay the die head with the index numbers facing up. Loosen the clamp lever and place the throwout arm toward the open position. Then lift the lock washer from the gauge bar slot and slide the assembly past the gauge bar slot as indicated on the head assembly.
Next, select the correct set of dies for the desired pipe size and insert them into the corresponding slot up to the line on the segment. Each die segment is indexed and must correspond to the numbers on the die head. In addition, die segments are manufactured in sets according to size and are not interchangeable. Once the dies are inserted, slide the clamp lever and throw out the arm assembly back toward the gauge bar slot. After the tongue on the lock washer drops into the gauge bar slot, the clamp arm can be secured.
Now you can begin setup for threading. Slide the work piece into the chuck assembly, making sure the pipe is centered and securely held in place by the grips.
Lower the roll cutter to the desired length, tighten the handle about one quarter turn per each revolution, and repeat until the pipe is cut through.
This will leave a burr on the inside diameter of the pipe, which must be removed to ensure proper flow through the pipe.
To remove the burr, insert the (flute) reamer into the work piece and rotate until the burr is removed.
A minimal amount of pressure will remove the burr completely and eliminate possible flaring of the pipe end.
After the burr is removed, adjust the die head to the desired size then loosen the clamp lever until the reference marks on the throwout arm collar and gauge bar are aligned.
To begin threading, place the throw arm in the closed position and slide the die segments over the end of the work piece.
Once proper thread length is achieved, the end of the pipe will become flush with the ends of the die segments.
To finish the threading process, simply flip the throw arm to the open position.
In addition, there are a few key things to remember during the threading process of CW pipe:
- Die segments should move freely, so each die slot should be cleaned thoroughly to remove shavings and debris.
- The pipe threads and die segments must be flooded with thread-cutting lubricant throughout the threading process.
- Never stop the threading process with the dies engaged. This will cause damage to the dies and pipe threads.
- It is good practice to clean all shavings from die segments prior to cutting each thread. A wire brush to remove shavings or debris from pipe is a good method to use.
- Pipe threads should be checked with a NPT L1-threaded ring gauge to ensure proper makeup.
- “Pipe dope” or Teflon tape can be used to reduce friction during makeup.
- A proper thread should be free from chips or tears over the entire length of the pipe.
Easy threading on CW pipe means that less wear and tear on the equipment. The threading process also makes the production of CW pipe faster, generating cost savings for contractors.
However, not all benefits of CW pipe are tied to its threading ability. At Wheatland, we offer an A53 CW pipe with numerous additional benefits.
Additionally, our CW pipe is coated with MIC shield coatings to combat microbiologically influenced corrosion. It has no hard spots or hard seams, and is manufactured on the most technically advanced CW mill. Our CW pipe is also ideally suited for welding, grooving and bending. Lastly, our CW pipe meets the stringent ARRA Requirement for Made in America products.
For more information on our A53 CW pipe, please visit our product page and download our brochure.