When should the pressure-tightness test be conducted on a newly installed product piping system?

The pressure-tightness test should be conducted on a newly installed product piping system before it is covered or placed in use. This testing phase is crucial because it helps ensure that the piping system is free of leaks, which is vital for preventing product loss and ensuring environmental safety. Performing the test at this stage allows for any potential issues to be addressed before the piping is buried or hidden, which would make subsequent inspections and repairs more difficult and costly.

Conducting the test after backfilling or once the system is in use does not allow for easy access to the piping system to address any leaks that might be present. If the test is done immediately after installation, while it is a good practice, it is even more critical to complete it before any additional layers, such as backfill, are applied, as this ensures the system is verified for leaks in its final placement conditions. Therefore, testing before covering the system is the most effective time to ensure integrity and compliance with safety standards.