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Benefits of replacing pressure decay testing with tracer gas testing

30 Jun 2015
Description

GLOBAL MARKETS ARE INCREASINGLY ASKING COMPANIES FOR MORE COST-EFFECTIVE PRODUCTION PROCESSES WHILE SIMULTANEOUSLY DEMANDING HIGHER PRODUCT QUALITY. THIS CHALLENGE REQUIRES INTEGRATED QUALITY TESTING METHODS THAT REDUCE UNIT COSTS AND, AT THE SAME TIME, IMPROVE PRODUCT QUALITY.

Production managers are faced with special challenges in the industrial leak testing sector. On the one hand, requirements regarding the leak-tightness of a component are often not available or not clearly specified. On the other hand, the variety of test methods and their levels of performance are frequently unknown. INFICON’s innovative leak testing technology, based on the tracer gas principle, has technical measuring advantages compared to pressure-dependent test methods. Every required quality class has a cost-optimized test method.

 

Starting points for selecting a suitable leak testing method include the requirements for leak-tightness of the component as well as the stability of ambient conditions in the testing location.
 
The leakage rate is the specification for the leak-tightness of a component. This must not exceed the maximum permitted loss
of content (operating medium) of a component over the course of its lifetime. As the operating medium does not usually correspond with the necessary tracer gas used for leak testing, conversion to the corresponding gas leakage rate must take place. Empirically determined values are available for components which were filled with fluid.
     Leak testing methods which are not particularly dependent on ambient conditions, especially the temperature, are advantageous. Within industrial leak testing, indirect test methods are particularly common; this is where the results are expressed as a leakage rate based on a change of pressure within a component, whereas with direct test methods, the actual gas leakage is measured based on a tracer gas.
 
GOOD REASONS FOR YOUR CHANGE
 
1 SAFER AND FASTER TESTING PROCEDURES –DESPITE TEMPERATURE FLUCTUATIONS
Differential pressure tests need stable temperatures. Temperature effects due to air-conditioning systems, drafts andsun, heat radiation from production facilities or fluctuating test part temperatures can be compensated for only to a limited extent and lead to faults in the testing process.
 
Here the INFICON trace gas method provides a remedy: it measures the leaking gas flow directly so that the temperature effect becomes negligible. Even very hot or cold test parts can be tested without a problem and without delay. A strong case for more efficiency in your testing process.
 
2 EVIDENCE OF THE SMALLEST LEAKS –EVEN WITH LARGE-VOLUME COMPONENTS
The differential pressure test measures the pressure change in the test part caused by the leak and not the amount of outflowing gas. Drawback: a very small leak in a large-volume component produces hardy any change in pressure and thus is not detected.
Contrast this with the INFICON trace gas method: here the outflowing gas is measured directly. Even the smallest leaks in very large-volume components are detected.
 
3 REDUCE UNIT COSTS –WITH RECOVERY UNITS
The trace gas testing entails costs for trace gases that, however, you can offset by using a simple recovery unit. In addition, the INFICON measuring technology allows the most minute test gas concentrations, which saves up to 95% of the costs depending on the application.
Last but not least: the differential pressure test also creates costs - for keeping the air clean, drying and compressing the test air.
 
4 MORE SAFETY – DUE TO THE LOW TEST PRESSURE
Conventional test methods require high test pressures to generate a detectable leak rate despite their low measurement sensitivity. Drawback: faulty and incorrectly attached high pressure lines and defective test parts pose serious risks under high pressure.
The INFICON solution: leak detection devices with low-pressure testing options. This increases the operating safety and lowers your outlays for protective mechanisms and test gas filling.
 
5 ELIMINATE LEAKS – THROUGH EFFECTIVE LOCALIZATION
With the INFICON trace gas method you locate leaks quickly and precisely - also in connection with pressure-dependent testing or integrated into manual or automated leak testing according to the sniffer method. You can then eliminate the leak, check the success of the repair and return the component to the valueadded chain.
 
6 TESTING OF SENSITIVE OR FLEXIBLE COMPONENTS – WITH TRACE GAS ONLY
Each pressure-related change in the component’s volume follows a change in pressure. This makes the pressure drop testing of flexible or unstable components impossible.
For the purposes of this application, INFICON offers you accumulation leak detection products that detect even the smallest leaks at minimum fill pressures. A special bonus: The very simple testing methodology guarantees you low investment costs.