Production process of metal expansion joint.

Metal expansion joint is widely used in various industrial pipeline system by the advantages of high temperature resistance, corrosion resistance and long service life. This article will introduce the process and relevant equipment and tools to make one metal expansion joint.

1.    Preparation

Take the DN600 metal expansion joint for example, the first step is to prepare the correct material of pipe for expansion joint. As to make a pipe, you need to use shearing machine to cut the metal coil or sheet into required dimension. Then the coil or sheet should be rolled by a rolling machine into a round shape before welding. The next step is to weld. Normally seam welder is the best tool to weld the short pipe, easy and low consuming. Pipe finished, the preparation job is done.  

2.    Bellow expansion joint production

Regarding to the expansion joint production, there are many equipment choices. But considering the capacity and tooling cost for big size expansion joint, we decided to use FUGE auto mechanical punch bellow forming machine. At the beginning, we will need to input the bellow specification through HMI touching screen, such as ID, convolution height, pitch, thickness. Then you can put the pipe on the auto rotating salver of the bellow machine, adjust the position and make sure the pipe is tightly hold by the auto clamping devices. Press “start” on the control panel, the bellow will be formed automatically. The display light will turn on after the bellow well done. Take the bellow down and get ready for final assembly.

3.    Assembly

Prepare the necessary accessories, and you can start the assembly and welding of the expansion joint. The accessories should be strictly adhering to the expansion joint, making sure the complete structure to be stable. Using the proper welding technology and material can ensure the welding quality and avoid welding defects.

4.    Quality inspection and package

After the final assembly, you need to inspect the quality of metal expansion joint, as to ensure a qualified performance and outlook. Quality inspection includes pressure test, air tightness test, outlook test etc. Only those approved bellow can be packed for delivery. The cargo should be well packed based on product features and customers’ requirement, in case of any damage or harm to the cargo during the transportation.

As a conclusion, there are four steps to finish an expansion joint assembly: Pipe Preparation, bellow production, assembly, quality inspection and package. Each procedure requires strict quality control and precise operation, as to guarantee the final product can meet all requirements.