What procedure should be followed with lines that have held products prior to testing?

Purging the lines that have held products prior to testing is essential for ensuring the safety and accuracy of the testing process. The purge procedure involves the removal of any residual product from the lines, which helps to eliminate contamination and ensures that the testing accurately reflects the condition of the lines without interference from previous contents. This is particularly vital in contexts like underground storage tank assessments where the integrity of the lines must be evaluated without the influence of remaining materials.

By purging the lines, operators can reduce the risk of incorrect test results that could lead to faulty assessments of the storage system. It is a critical step in preparing for further actions such as inspections, maintenance, or new installations, ensuring that the testing environment is as clean and neutral as possible for reliable outcomes.

Other methods, such as flushing or filling with water, do not equate to the thorough removal of product and could still leave residues or introduce new variables that may interfere with the testing. Inspections alone cannot ensure that the lines are free of hazardous materials, which is why purging is the most effective and appropriate procedure.