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Before you can test for leakages you need to understand what a leakage is. Teesing has created a comprehensive document on leakage to understand, find and prevent leakage in your application.

Why perform a leakage test?

To avoid damages caused by a leak, such as damaged products or assemblies and production downtime. Financial consequences are more serious when a machine cannot produce according to schedule than the costs of leak testing itself.

Teesing offers custom leak testing of applications made to be installed in your system. This is done with a very sensitive instrument that can quantify the amount of leakage to great precision. The Inficon Sensitor Sentrac is far more accurate than traditional methods of testing for leaks. This accuracy is of course of great relevance for the high-tech industry with its ultra-clean environment and extreme precision.

Testing before the delivery of the products or assembly offers you the guarantee of a constant product quality prior to the products entering your process.

Read what you can do yourself to minimize the risks of leakage and the possiblities Teesing can offer in ‘Understand, find and prevent leakage’.

Making your system 'leaktight enough'

What is in fact important about leakage is that it does not exceed the requirements of your system. Leakage occurs in different volumes and frequencies, and some materials may be leaktight for some applications and not for others. What is important is fit for purpose. The document below explains at length how leaktightness is a relative concept and what it can mean for your specific situation.

Preventing leaks in industrial systems as much as possible has many advantages. Not only does it prevents extra financial costs or a disruption in your production process but it also ensures that product failures are eliminated as far as possible and the leak is tracked down faster.

Leak-free does not exist, but insight into the different materials and types of leakages can be of great benefit. Download the document!


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Teesing Engineering has created a comprehensive document on leakage, materials and industrial systems. So often the request reaches us: ‘make our system leaktight’. Unfortunately we have to disappoint these clients, explaining that leaktight does not exist.


  • Background
    • What is a leak?
    • Leaktight?
    • Factors that may cause leakage
    • Permeation
    • Leakage rate
    • Liquid and gas
      • The difference between liquid and gas
      • Viscosity
    • Flow types
    • Factors which can influence leak detection
      • Temperature
      • Leaks blocked by liquids
      • Material flexibility
      • Seal and surface treatment
  • Leak detection methods
    • Bubble test
    • Soap spray methods
    • Pressure test with air
      • Pressure decay test
      • Differential pressure test
      • Pressure increase test/vacuum decay test
    • Tracer gas leak detection
    • Mass spectrometer analysis (residual gas analysis)
    • Dye penetration test
  • Tracer gas leak detection
    • Tracer gas
      • Helium
      • Hydrogen (forming gas mixture)
      • Comparison
    • Sniffer leak detection
    • Integral leak test
    • Calibration
    • PPM
    • Inficon Sensitor Sentrac

  • Additional Information
    • Frequently asked questions
      • Why should I perfom a leakage test? 20
      • What is the reason that the test pressure is always higher or the same as the operational pressure?
      • Can I assume that if I don’t see bubbles during the bubble test that there is no leak?
      • Do I have to perform a leakage test with air before perfoming a tracer gas test?
      • Do I have to flush the test product with tracer gas before starting the real leakage testing?
      • Is a the leakage rate of helium the same as the leakage rate of hydrogen?
    • Sealing methods
      • Thread seal types
      • Surface seal types
    • Other test methods
  • Appendix
    • Appendix 1: Conversion factor
    • Appendix 2: Comparison table
    • Appendix 3: Test certificate
    • Appendix 4: List of terminology
    • Sources