Leak testing is a critical step in ensuring the safety, performance, and reliability of countless products and systems, from medical devices to automotive components, and more. However, designing an effective, accurate leak test can be difficult. Manufacturers can easily fall into common pitfalls that compromise the accuracy and efficiency of their leak test process. In this post, we’ll explore 4 common leak testing mistakes, how they can impact your results, and practical strategies to avoid them, so you can maintain quality and confidence in your processes.
1. Trying to Test Too Quickly
A common mistake manufacturers make with their leak tests is trying to test too quickly. In an attempt to achieve a quicker cycle time, manufacturers may rush the stabilization process and/or the measurement/test process, which can both greatly affect the accuracy of test results. While it can be tempting to speed up the leak test process, you need to make sure you are maintaining the integrity of the test to ensure a good reliable test measurement.
If you bring a part up to pressure and/or isolate pressure without adequate stabilization time, thermal changes, porosity, and part movement can cause instability in the part, making it impossible to get a reliable, repeatable leak measurement. And if you rush test time, you may not give the test long enough to distinguish between good and bad parts.
2. Not Changing Your Cycle Time to Accommodate a New or Updated Leak Rate
When your target leak rate changes, you must change your cycle time to accommodate that change. This is a somewhat common occurrence on the production line. For example, a customer may change their leak rate from 5 sccm to 2.5 sccm. In this case, you have decreased your leak rate by half, so you must double your test time to ensure an accurate measurement.
3. Ignoring the Impacts of Part Temperature
Part temperature is a very important variable you must control when designing your leak test. Temperature can become an issue in various ways, including thermal effects that can occur during the fill process, or if the part was subjected to heat in process(es) shortly before the leak test station. In these cases, you must design your test to compensate for the change in temperature. This can include adding a longer stabilization time to allow the part to return to room temperature before the leak test measurement, or using a leak test method that will not be impacted by temperature, such as tracer gas leak testing.
4. Not Ensuring an Effective Seal
Manufacturers often underestimate how difficult it can be to sufficiently seal parts for an effective leak test—but it is so important. The seal(s) is a major component of ensuring an accurate leak measurement during your test cycle. It is not as simple as applying an O-ring and relying on the part to compress it enough to ensure an adequate leak seal. The degree of the seal location, durometer, surface finish, seal lifetime, level of compression, and more, must be considered to ensure an adequate seal for your leak test.
Is Your Leak Test Setup Skewing Results? Contact Us if You’re Not Sure!
CTS has over 40 years’ experience helping manufacturers design and optimize leak test processes to ensure accurate, reliable leak test results. Our team can help you review your current test setup to ensure you are not making any mistakes that could be skewing your test results and provide guidance and support in making the required alterations as needed.
Contact us today to speak with a leak test expert about your test!