is that there is not a way to evaluate the weld seam quality. Additionally, the weld has to be coated with conductive material. Leak-tightness testing Leak-Tightness Testing or Leak Testing utilizes either liquid or gas to pressurize a part. This type of testing is typically conducted on tubes, containers, and vessels. Another way to leak-test one of these structures is to apply a vacuum to it. One of the advantages is that it is a quick simple way for the weld flaw to be detected. Additionally, it can be used on multiple materials and part shapes. On the other hand, it has a few disadvantages. Firstly, there is not a way to evaluate the weld seam quality. Secondly, it has an explosion hazard associated with it if over pressurization occurs during testing. Last, it is limited to tubular structures., See also Butanone Electrofusion Heat sealer Rheological weldability for semi-finished polymer parts Thermoplastic staking References Further reading J. Alex Neumann and Frank J. Bockoff, "Welding of Plastics", 1959, Reinhold publishing. Safety in the use of Radiofrequency Dielectric Heaters and Sealers, Michael J. Troughton, "Handbook of Plastics Joining, A Practical Guide", 2nd ed., 2008, Tres, Paul A., "Designing Plastic Parts for Assembly", 6th ed., 2006, Grewell, David A., Benatar, Avraham, Park, Joon Bu, "Plastics and Composites Welding Handbook", 2003, Packaging machinery