The pipes are creaking, and the flanges are leaking as the steam escapes from the old industrial parts. The flexible bellows protect the piping system from heat and vibration, but their failure can cause problems for the entire system. This replacement process is not easy because of the age, the rust, and the old specifications that must be taken into account. It is very important to choose the correct metal expansion joint.
Start by studying the existing bellows and determine the sizes, length, number of convolutions, material grade, and end fitting type. Take measurements for the distance between the pipes as well as the temperature, pressure, and movements. Select the proper bellows based on whether they are axial, lateral, or angular in relation to the movement of the pipes. Apply precautions while dismantling the existing bellows through the use of temporary supports, and thereafter remove the bellows and clean the faces of the flanges.
Various Ways to Effectively Replace Bellows in Older Industrial Plants
Reinstallation of bellows in old buildings needs proper planning owing to their age and limitations of accessibility. The process of replacing bellows includes evaluation of the existing bellows, choosing the material, uninstalling the old bellows, and installing new bellows.
- Inspect the existing bellows thoroughly
Start off with a keen observation of the affected area. This could be achieved by being on the lookout for signs of any possible defects, for example, cracks that could point to structural failure; corrosion that might suggest material failure; and bulges that could show that there are defects hidden underneath. It is important to know where the defect happened because this will help identify the cause of the defect.
- Measure the actual gap and movement
Never rely solely on the drawings. Always measure the actual space between the pipe ends. Determine all your requirements for axial, lateral, and angular movements. A metal expansion joint manufacturer can assist you in meeting all those specifications. Incorrect measurement leads to premature failures.
- Confirm pressure and temperature ratings
Prior to installation, determine the operating pressure and maximum temperature of your system. Record the figures, then compare them to the specifications of the new joint you wish to install. Make sure that the joint is able to handle the pressures and temperatures that are at least as high as those your system requires. It may be even more important to consider a sufficient safety margin for older facilities, where wear and tear can affect performance.
- Plan temporary pipe supports
With the removal of the supporting structure, it becomes weaker along its entire length. To prevent sagging and misalignment, you need to put temporary supports in place before any cutting. The temporary supports will help ensure that everything remains stable and secure while work is underway on the project.
- Install the new joint correctly
Install the correct gaskets on the new bellows. Tighten bolts in a crisscross fashion. Refer to the torque specs provided by the supplier. Manufacturers of metal expansion joints normally provide such information. Ignoring these instructions can result in leakage.
- Test the system slowly
Start with a relatively easy test in which not much danger is posed. Notice whether leakage is occurring through the flanges, as it is important to ensure the safety of the whole system. Increase the pressure and see how the system reacts under the new pressure. The movement of the bellows is particularly important since unusual behavior could be indicative of trouble.
Conclusion
Installation of bellows in old industrial plants should be done cautiously by checking the size and installing them properly. By doing this, it will help avoid leakages and downtime and ensure safety in the process.