The qualification criteria for the expansion joint pressure test are mainly as follows:
Leakproof
- Under the test pressure, the various connecting parts of the expansion joint (such as flange joints, welding points) and their own sealing structure (such as the seal of the bellows) should not leak. When observed, no liquid or gas seeps out and no bubbles form.
The deformation meets the requirements
- When the expansion joint is subjected to the test pressure, it will produce a certain deformation, and the deformation amount should be within the specified range. The specific deformation standard varies with the type, specification and design parameters of the expansion joint. The maximum allowable deformation value is usually provided by the manufacturer and cannot be exceeded during testing.
Structural integrity
- During the pressure test, the internal structure of the expansion joint (such as the wave crest and trough of the bellows) should not be damaged by rupture, tear, or collapse. The whole expansion joint should be able to maintain its original structural form to ensure normal use in the future.
