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
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)
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.
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.