HENAN SHUNYING

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Limit expansion joint use method and cause of damage

2019.12.02

The limit expansion joint uses a flange connection method. This connection method is much more convenient than traditional welding, and it is too convenient for future use and maintenance.

The use method of the limit expansion joint is to connect one end of the flange of the expansion joint with the flange on the pipe or the flange of the valve pipe fitting, and insert the pipe into the socket at the other end. The insertion length should be slightly less than the total length of the product. The insertion end is marked in advance with a preparation length marking line for accurate grasp. Before installation, check whether the adjustment bolt is in the most relaxed state and the rubber seal in the socket should be free from compression. When inserting the tube, apply soapy water to the tube in advance to reduce friction and facilitate insertion. After the pipe is inserted, the adjusting bolt should be tightened gradually and cyclically so that the rubber sealing ring in the socket is tightly combined with the pipe. The limit expansion joint is used at the end of the pipeline (that is, the end of the pipeline), and an end support pier should be considered to offset the thrust generated by the medium in the pipeline.

For the limit expansion joint of the inner sleeve, attention should be paid to whether the direction of the inner sleeve is consistent with the direction of the medium flow. Whether the plane of the hinge rotation and the displacement rotation of the main limit expansion joint is also consistent, and the use of deformed expansion joints is prohibited. To adjust the installation of the pipeline, this will affect the normal service life of the expansion joint and increase the burden on the pipeline. The limit expansion joint is mainly a compensation element that uses elastic elements of the corrugated compensator to perform effective expansion and contraction to absorb conduits, pipelines, etc. to produce dimensional changes.

What is the reason for the damage of the limit expansion joint?

The use of the expansion joint must first consider the applicable temperature of the transmission medium. Generally speaking, the temperature of the medium cannot be higher than 300 degrees. How the medium is acidic or alkaline, otherwise the expansion joint is easily damaged. In addition, the retractable length of the position of the expansion joint joint is not enough during the use, forcibly exceeding the retractable length, and the expansion of the shrinkage range may cause damage to the expansion joint.

Also, the strength of the interface part of the limit expansion joint is not high enough. If the installation method is not accurate, the strength of the joint will become low, which may cause damage to the expander. When the expansion joint is installed in the open air, avoid sunlight exposure and contact with acidic and alkaline items. Otherwise, the expansion joint will be corroded and damaged for a long time.

The last point is also very important. After the limit expansion joint is installed, if the pipeline is severely deformed, the expansion of the expander beyond its expansion range will cause damage to the expander. In summary, it is the analysis of the cause of the damage of the expander. If you understand the cause of the damage of the expander, you must avoid these situations during the construction and pipeline maintenance to ensure the long-term stable operation of the pipeline.