The Importance of Pressure Decay and Leak Testing

Plumber testing compressor leaks.

Leak testing is an important quality control measure for many of today’s industrial products, including drums, containers, storage tanks, radiators, and valves. Processes such as bonding, gasketing, and welding also require leak testing to ensure the safety and quality of the products that go through them.

Popular industrial leak testing methods include helium ion detection and pressure decay. Helium ion detection requires expensive equipment and is quite a complex process. Pressure decay, on the other hand, is relatively simple and does not involve complicated, costly equipment, making this technique among the most popular leak testing methods. Plus, this type of testing can be easily automated.

Pressure decay is a relatively old leak testing method that has been used for many years. The term “pressure decay testing” is often used interchangeably with “vacuum decay testing,” as both methods determine leak rates based on pressure or vacuum.

The Methodologies of Pressure Decay and Leak Testing

Pressure decay involves pressurizing the piece to be tested, isolating the piece from the source of pressure, then monitoring it for pressure loss. If there is subsequent loss of pressure, it can be concluded that the product has a leak. The length of time required for this process depends on the size of the object being tested. Generally, the larger the size of the object, the longer the cycle time for the leak test.

When performing a pressure decay leak test, technicians measure the internal volume of the part for testing before pressurizing the part. Once the test begins, technicians measure any subsequent pressure drop in the part being tested. They can then compute the leak rate.

A leak test using pressure decay can be performed using either a gauge-type transducer or a differential pressure transmitter. Although very effective for detecting very small to small leaks, making use of a gauge-type transducer typically takes more time. A differential pressure transmitter, on the other hand, allows for more sensitive leak detection. This is also much faster than utilizing a gauge-type transducer.

How Pressure Decay and Leak Testing Are Used Industrially

Pressure decay leak testing produces quantifiable results. Therefore, it is especially well-suited for applications in which test results must be documented and test protocols validated. Medical devices, for example, need to meet strict quality standards.

Pressure decay leak testing is also valuable for process control in manufacturing settings. For example, by tracking leaks via a control chart, a machine operator can stop a production process temporarily until the cause behind the leaks is detected and resolved.

Differential pressure transmitters allow for faster pressure decay leak test results, making this method ideal for high-volume production in the automotive, consumer goods, and medical device industries, among others.

Choosing the Right Leak Testing Method

Industrial leak testing is crucial for detecting faults in industrial products, ensuring that production quality in assembly line processes is maintained.

Among the many industrial leak testing methods available, pressure decay leak testing remains one of the most popular options thanks to its easy implementation and automation. Plus, the pressure decay method is inexpensive and does not require complicated, costly equipment.



Image Credit: Dagmara_K/


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