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Leak Detection - Know Your Leaks

leak detection

Know Your Leaks

To combat leakage, choosing the right components and installing them correctly can save time and money. When maintaining fluid systems, remember:

  • Common causes of leakage include
    • Unreliable metal-to-metal seals
    • Improperly installed tube fittings
    • Poor tubing selection  or preparation
  • Making highly reliable metal-to-metal seals is a difficult task—follow manufacturer guidelines precisely
  • Leaks occur most often in valves and connectors because they are the most prevalent components in facilities
  • A good leak detection  program increases worker safety and decreases risks to your operation

Types of Leaks

real leak

Real leak

Occurs when a pressure barrier fails to contain or isolate a system fluid from the surrounding environment (result of cracks or gaps between sealing surfaces or permeation through seal materials)

virtual leak

Virtual leak

A release of internally trapped fluid into a fluid system due to material outgassing (escape of gas from a material under test in a vacuum), absorbed or adsorbed fluids, entrapment in cracks, or deadlegs.



The passage of fluid into, through, and out of a pressure barrier that has no holes large enough to permit more than a small fraction of the molecules to pass through any one hole. 

leak detection

Learn Leak Detection

When testing for leaks, there are four main nondestructive test (NDT) methods to consider:

  • Bubble Testing - test using immersion or film solution techniques
  • Pressure Leak Testing – hydrostatic and pneumatic tests for detecting leaks in an entire assembly
  • Pressure Change Measurement Testing – test for leaks by detecting changes in pressure
  • Mass Spectrometry Testing – typically referred to as helium leak testing. Measures the amount of tracer gas, usually helium, present in the unit being tested. The presence of the gas indicates a leak.
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