The leak testing of pipe joints, fittings and tubes in refrigeration and heating components, such as compressors and coils, is vital throughout assembly manufacturing.
Conventional sniffer testing is not a reliable technique to detect small leaks, with the permissible leak rate as small as 0.5 grams of refrigerant loss per year.
In order to detect helium escaping from a leak, sniffer tests sample leaks compared to background. Yet, background helium concentration fluctuations can make it challenging to distinguish good from bad products consistently and can lead to false accepts that passes leaking assemblies. This can occure as operators zero their detection device to higher concentrations of background helium.
CTS’ nitrogen purge leak testing eliminates the factors affecting fluctuating background which helps influence greater measurement accuracy:
- Remove operator subjectivity and dependence by automating the test to gather quantitative measurement
- Decrease false failures to gain a more repeatable test process
- Solve the problem of background contamination influencing testing results at a lower cost than hard vacuum mass spectrometer testing
The video below details more about nitrogen leak detection technology from CTS.
Video Credit: Cincinnati Test Systems
What is the Nitrogen Purge Leak Testing Procedure?
The CTS nitrogen purge solution is a tracer gas leak test system that combines a mass spectrometer, the TracerMate II instrument to control the test and supply results and the CTS purging clamshell, which is clamped onto the joint(s) which are being tested.
The CTS nitrogen purge clamshell device possesses outer and inner chambers that surround the part test area. The chambers have ports that force out ambient atmosphere by permitting nitrogen to enter the cavity.
Image Credit: Cincinnati Test Systems
The clamshell inner chamber collects the tracer gas leaking from the part throughout the leak test cycle controlled by the TracerMate II. The outer chamber then supplies a constant low positive pressure nitrogen gas curtain to effectively isolate the inner chamber and prevent ambient background from entering.
The gas from the chamber is drawn into the mass spectrometer and, in order to measure the amount of tracer gas, this analyzes the gas mixture. The mass spectrometer conveys the results to the TracerMate II. As the instrument determines and signals a ‘pass’ or ‘fail’ (green lights or red lights) for the nitrogen leak test, the measurement readings are then shown on the TracerMate II display.
Turnkey Solution for Leak Testing Pipes, Joints, Tubes and Fittings
The TracerMate II is a ‘one stop’ leak detection system that enables test pressure, evacuation, tracer gas backfill, a gross leak test and the exhaust process. This high-sensitivity tracer gas system is offered either as instrumentation or integrated as a turnkey test system with custom handheld devices.
The handheld nitrogen purge clamshell devices from CTS are custom designed to your application, small and easily maneuvered to clamp over fittings, components and joints. The nitrogen purge custom benchtop test fixtures are designed to fit a wide variety of applications.
Image Credit: Cincinnati Test Systems
Complete Leak Test Station for Heating and Refrigeration Components
CTS is able to integrate the Nitrogen Purge technology into a complete solution such as the TracerMate II HVAC-R Portable Leak Test System. The system allows the utilization of however many probes as needed on up to 20 different leak locations.
Nitrogen Purge Systems Designed for Accurate Helium Leak Testing
The patented nitrogen purge leak testing system from CTS can eliminate false leak failures. The patented clamshell device employs low pressure nitrogen to create a helium-free environment, enabling the mass spectrometer gas analyzer to sample and detect micro-leaks.
Nitrogen purge leak testing is the ideal technique for detecting micro-leaks in tubing, pipe joints and small parts. As they are more reliable than other tests, a number of which are easily influenced by environmental factors, industries ranging from medical to HVAC/R choose tracer gas systems.
- Detects leaks as low as 10-6 scc/s
- Compatible with numerous gases, including forming gas, helium and refrigerants
- Versatility for utilization in a wide variety of cooling and heating applications
- Higher sensitivity for better leak detection accuracy: decreases background to 10-7 atm-cc/s range
- Low cost tracer gas testing technique
Image Credit: Cincinnati Test Systems
Enhance Your Tracer Gas Testing Accuracy with Nitrogen Purge Technology
Cincinnati Test Systems’ nitrogen purge systems help the user to improve efficiency and gather more accurate leak testing results.
This information has been sourced, reviewed and adapted from materials provided by Cincinnati Test Systems.
For more information on this source, please visit Cincinnati Test Systems.