Vacuum leaks are distinct from the line leaks commonly encountered in compressed air environments. Many of the usual techniques, such as bubble testing or audible noise, are largely ineffective. Vacuum leaks may be microscopic and still capable of wreaking havoc, but below are some tried and true methods for identifying industrial vacuum system leaks so they can be fixed as soon as possible.
Pressure Rise Test
Pressure rise testing is used to measure pressure within the vessel by how it rises during a specific time span. Although this test is good at identifying leaks, it won’t necessarily tell you where it is. In a scenario where a vessel is leaking faster than anticipated, it will often be necessary to perform an inspection that is more detailed. As you go deeper into the vacuum, the lighter gases like Helium can be sprayed in the area surrounding the leak. Helium ingress is detectable via mass spectrometer, which will allow technicians to ascertain what is leaking and wear. Pressure rise tests work best for vacuum levels which are moderate to fine, but don’t do well for vacuums which are rough.
The solvent test is the best option for a leak within a rough vacuum. The reason for this is because of the usage of alcohol and acetone, which will be applied to components via spray which will produce a change that is measurable by vacuum gauge. The gauge will help technicians identify the leak.
What Causes Vacuum Leaks?
Vacuum leaks can be caused by structural holes, seals which have become contaminated or gases which are emitted from the walls of the vessel. Such leaks can be difficult to detect, even by trained personnel since they can be very small. Vacuums must be completely free of leaks in order to operate safely efficiently.
A leak is the result of changes in pressure coming from an opening between the interior of the vacuum and the surrounding atmosphere. They can also occur due to vapor or gas progression. These changes in pressure are undesirable as they can lead to additional damage, culminating in the formation of solids or even an explosion.
It should also be emphasized that leaks come in different forms. The two most common are virtual or real leaks. Virtual leaks are those in which the gas load is expanding from within the vacuum. They are usually accompanied by outgassing, which results from liquid that becomes vaporized within the chamber. Real leaks enter the vacuum from a source that is external to it.
How To Prevent Vacuum Leaks
Proper maintenance is the key to preventing leaks before they occur. Leaks are common near areas where connections are present, especially those which have been worked on recently. Sometimes they occur over time due to wear or corrosion. It is essential that technicians inspect the system regularly to identify leaks, or things which could lead to them, before the issue becomes worse.