The tightness leak detection, also known as airtight test or pressure leak test, is a common pneumatic pressure test. The airtight leak detection usually uses air, nitrogen or helium as the test medium to check whether the testing object has leaks, thereby verifying the tightness performance of the testing. The process of the tightness leak test is as following. First of all, slowly increase the testing pressure to the preset pressure (the testing pressure is generally set to 1.15 times the design pressure). Then turn off the pressure source and maintain the pressure. After the pressure maintenance period, three methods can be used to determine whether the tightness is qualified: bubbling method, pressure drop method, and pressure difference method.
1. Bubbling Method Tightness Leak Detection
This is the most intuitive tightness detection method. Apply some water or soapy water to the outside of the testing object, or directly immerse the testing object in water. And then inject the air or gas at the required pressure into the testing object. Finally, visually check if there are bubbles, thereby determining whether there is a leak and find out the leak point.
Features: Simple operation, the test results can be determined by visual check and the leak point can be quickly found.
2. Pressure Drop Method Tightness Leak Test
It determines whether the testing object is leaking by the pressure drop of the gas inside the testing object. First of all, inject the air or gas at the desired pressure into the testing object, and then maintain the pressure for a period of time. After the pressure maintenance period, observe the pressure gauge. If the pressure-drop exceeds the allowable pressure-drop, it proves the testing object is leaking.
Features: Simple operation and especially suitable for items that cannot come into contact with water, such as electronic components.
3. Pressure Differential Method Airtight Leak Detection
It uses high-precision instruments to measure and compare the small pressure difference between the testing object and the standard product, so as to determine the tightness of the testing object.
Features: The test accuracy is higher, but the operation is complicated and the cost is high.
As an experienced pressure test equipment manufacturer, Senwell provides manual and automatic tightness leak detection machines for uses to choose from. In addition, our engineers will match and recommend suitable pneumatic test equipment according to user’s specific application.
