Maintenance and Usage of Rotary Joints

What is Steam Rotary Joint?

The steam rotary joint can be likened to the "throat" of a paper machine; it serves to connect stationary steam piping to a high-speed rotating dryer cylinder, efficiently delivering steam into the cylinder while smoothly discharging the resulting condensate. This device constitutes a critical link in ensuring the efficient and uniform drying of the paper web. Because of its simple structure and low price, it has good market demand. However, steam rotary joint is prone to rust and cannot be used for a long time, which is a problem that needs to be solved. Below, Sun Hong will explain the use and maintenance of rotary joint based on practical experience.

Usage and Common Issues of Steam Rotary Joint

For rotary joint, it's better to use them than not to. Some production lines operate 24/7 due to tight schedules. While this accelerates equipment wear, it's actually beneficial for the rotary joint. Continuous use slows down rusting and prevents impurities from accumulating, thus extending their lifespan. Conversely, if the production line operates intermittently, impurities from the cooled steam and rust from immersion in water inside the joint will damage the seals.

in addition, standard daily maintenance can effectively extend the service life of steam rotary joints, but this requires ensuring correct selection and standard installation.

How to Maintain a Steam Rotary Joint?

To prevent the spherical surface of steam rotary joint from rusting, the spherical surface is made of stainless steel or undergoes special hardening treatment. This protects the spherical surface from wear and inhibits corrosion to a certain extent. If the steam rotary joint—with the exception of the sealing and support rings—is constructed primarily from ferrous materials (including the springs), the issue can be addressed through material selection and specialized processing (e.g., using stainless steel or applying surface hardening). Alternatively, one can focus on implementing proper maintenance and care procedures based on the existing configuration to extend the service life of the rotary joint.

• It is recommended to avoid immersing the steam rotary joint in water. Whenever the equipment is shut down, consider checking whether any water remains inside the roller and verifying that the siphon tube is functioning effectively. If the shutdown period is prolonged, manual drainage is advisable; If the downtime is long, it is best to drain the water manually. Alternatively, you can disassemble the water outlet pipe of the rotary joint to drain the water and test the drainage capacity of the siphon pipe.

• Place some high-temperature grease inside the rotary joint. Before installing the rotary joint, place more high-temperature resistant grease between the ball surface and the sealing ring. This will also prevent impurities from entering the sealing surface when the machine is stopped. Steam rotary joints mostly rely on oilless bearings for support. There is a very small gap between the outside of the bearing and the shell. The inside of the oilless bearing fits into the tube body of the tube. Therefore, it is helpful to put more high-temperature resistant grease on the oilless bearing near the tube body.

In conclusion, the steam rotary joint plays a vital role in ensuring stable steam transfer and efficient drying performance in paper machines. Proper usage and regular maintenance are essential to prevent common issues such as rust, seal wear, and leakage. A well-maintained steam rotary joint not only reduces downtime and maintenance costs but also contributes to consistent paper quality and overall operational stability.