This section was prepared in order to better inform the user of those factors which many years of experience have shown to be essential for the successful installation and performance of piping systems containing bellows expansion joints.
Inspection prior to Start-up or Pressure Test
Expansion joints are usually considered to be non-repairable items and generally do not fall into the category for which maintenance procedures are required. However, immediately after the installation is complete a careful visual inspection should be made of the entire piping system to ensure that there is no evidence of damage, with particular emphasis on the following:
- Are anchors, guides, and supports installed in accordance with the system drawings?
- Is the proper expansion joint in the proper location?
- Are the flow direction and pre-positioning of the expansion joint correct?
- Have all of the expansion joint shipping devices been removed?
- If the system has been designed for gas, and is to be tested with water, has provision been made for proper support of the additional dead weight load on the piping and expansion joint? Some water may remain in the bellows convolutions after the test. If this is detrimental to the bellows or system operation, means should be provided to remove this water.
- Are all guides, pipe supports and the expansion joints free to permit pipe movement?
- Has any expansion joint been damaged during handling and installation?
- Is any expansion joint misaligned? This can be determined by measuring the joint overall length, inspection of the convolution geometry, and checking clearance at critical points on the expansion joint and at other points in the system.
- Are the bellows and other movable portions of the expansion joint free of foreign objects?