Save costs and ensure the stability of your process through leak tightness.
Let Busch help maintain the leak tightness of your vacuum equipment.
Together with our TAPIR leak detector, our skilled service technicians precisely locate and quantify leaks. Thus ensuring that your process can continue to run smoothly.
Leak detection service
What are vacuum leaks?
A vacuum leak is an unintended or unwanted opening in a vacuum system. It allows air or other gases to enter or exit the vacuum system. The amount of air or gas that leaks out of a vacuum system is expressed as the leakage rate. Leakage rates depend on several factors, including the size and number of openings, gas type and pressure differences between the inside and outside of the system.
There are two types of vacuum leaks:
- Outside-in leaks, where ambient air or gas flows into the system.
- Inside-out leaks, where process gas or operating fluid flows out of the system.
What are the causes of vacuum leaks?
Vacuum leaks occur due to various reasons. These include issues like faulty or old seals that have become porous, damaged components, or improper installation of vacuum equipment.
What is the average size of a vacuum leak?
There is no average size of a vacuum leak, it can range from microscopic to large tears, depending on what caused it. The size of a vacuum leak can be determined by measuring the leakage rate, which is the amount of process gas or air that escapes from the system per second. Most technical leaks are too small to be seen with the naked eye. Helium leak detectors, like our TAPIR, provide the most accurate method for detecting and quantifying small vacuum leaks.
How do I test for vacuum leaks?
There are different ways to detect leakage with our TAPIR. The so-called spray test is suitable for components under vacuum. And the sniffing leak detection for components under pressure. The means of detection is the tracer gas helium or hydrogen.
The test methods are easy to perform and deliver accurate results, making TAPIR the perfect addition to your vacuum process.
Spray test
(components under vacuum)
The so-called spray test is the ideal test method for components under vacuum. This measurement principle has the highest sensitivity of all available methods. Air is removed from the test object that is suspected to have a leak, and TAPIR is connected through a flange. A test object can range from a vacuum furnace to a pipeline, a container, or other pieces of equipment. Helium or hydrogen is sprayed onto the outer surface of the test object with a spray gun kit (see figure 1). In case of a leakage, the incoming molecules are drawn in by the integrated turbomolecular vacuum pump of TAPIR together with its backing pump. The molecules enter an analyzer cell, which detects the tracer gas atoms.
Figure 1: Spray test
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Figure 1: Spray test
Sniffing leak detection
(components under pressure)
The sniffing leak detection is the perfect method for components under pressure. Helium or hydrogen is pumped into a test object, such as a piece of equipment, a pipeline, or a container, increasing the internal pressure. A sniffer probe, a tool designed to detect and locate leaks, can be purchased as an accessory and connected to our TAPIR. A service technician slowly and systematically guides the sniffer probe over the test object (see figure 2), just like a metal detector, only it’s searching for traces of helium or hydrogen. In the event of a leak, escaping tracer gas atoms are detected. And the leak can be localized precisely.
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Figure 2: Sniffing leak detection test
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Figure 2: Sniffing leak detection test
Integral leak detection
The spray test and sniffing leak detection can both be used for an integral leak detection test. Here, the test object is put inside a vessel, such as a plastic film or a rigid container (illustrated in grey in figure 3 and 4).
During integral sniffing leak detection, the test object is filled with helium (1). If there is a leak and helium starts to escape, it is captured in the vessel. The sniffing probe determines the increase in helium concentration over time and measures the leakage rate (2). This test is carried out at atmospheric pressure.
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Figure 3: Integral test at atmospheric pressure
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Figure 4: Integral test of objects which are enclosed in vacuum
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Figure 3: Integral test at atmospheric pressure
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Figure 4: Integral test of objects which are enclosed in vacuum
On the other hand, integral spray tests are performed under vacuum. The test object is connected to the leak detector and placed inside a vessel (3). To ensure precise test conditions and accurate results, the vessel is evacuated and filled with a defined quantity of helium. If there is a leak, then helium will penetrate the test object due to the difference in pressure. The leak detector measures the amount of helium inside the test object and determines the leakage rate.
Is Busch offering leak detection service?
Yes, we do. Contact us to arrange a leak detection service appointment. Our service experts are happy to help!
What are the two most common leak detection tests?
Spray test and sniffing leak detection are the two most common leak detection tests that use the tracer gas helium or hydrogen.
The spray test is the ideal test method for components under vacuum. This measurement principle has the highest sensitivity of all available methods. Helium or hydrogen is sprayed onto the outer surface of the test object. In case of a leakage, the incoming molecules are drawn in by the integrated turbomolecular vacuum pump of TAPIR together with its backing pump. They finally end up inside an analyzer cell. This cell detects the tracer gas atoms.
The sniffing leak detection is the perfect method for components under pressure. A test object is pressurized with helium or hydrogen. A sniffer probe, which is connected to our TAPIR, is then slowly and systematically guided over the object. In the event of a leak, escaping tracer gas atoms are detected, and the leak can be localized precisely.
What is the difference between qualitative and quantitative leak detection?
Qualitative leak detection initially only determines whether or not there is a large leak in the system under investigation. This is already possible from an inlet pressure of 100 mbar with the Busch TAPIR HL 2216 A. As the inlet pressure decreases, typically at 25 mbar, leak detectors are able not only to detect leaks but also to quantify them. This means that the size of a leak can be accurately determined based on the leakage rate.
Is there a difference between vacuum leak testing and pressure decay detection?
In a pressure decay test, also known as a vacuum decay test, a pressure vessel is filled with air until a target pressure is reached. Then the loss (decay) of that pressure is measured over a set period of time. On the other hand, there are several types of vacuum leak testing. For example, specialized devices such as our TAPIR leak detector can conduct two types of tests utilizing either tracer gas helium or hydrogen for detection. Vacuum leak testing offers quicker results compared to pressure decay testing and is also less sensitive to external factors such as temperature variations. Thus, the results are also more accurate.
What is the difference between the spray test and the sniffing leak detection?
The spray test is the ideal test method for components under vacuum. This measurement principle has the highest sensitivity of all available methods. Helium or hydrogen is sprayed onto the outer surface of the test object. In case of a leakage, the incoming molecules are drawn in by the integrated turbomolecular vacuum pump of TAPIR together with its backing pump. They finally end up inside an analyzer cell. This cell detects the tracer gas atoms.
The sniffing leak detection is the perfect method for components under pressure. A test object is pressurized with helium or hydrogen. A sniffer probe, which is connected to our TAPIR, is then slowly and systematically guided over the object. In the event of a leak, escaping tracer gas atoms are detected, and the leak can be localized precisely.
Both test methods are easy to perform and deliver accurate results.
