Leak Testing

Vacuum box and vacuum tube methods are commonly used in non-destructive testing (NDT) for leak detection in various applications, such as pipelines, tanks, and other pressure vessels. These methods are applicable for identifying leaks or defects in the welds and materials being tested. Here’s an overview of how these methods work:

Vacuum Box Method:

Principle:

The vacuum box method relies on creating a vacuum within a sealed chamber placed over the area to be tested. Any leaks or defects in the material will allow air to be drawn into the vacuum chamber, which can then be detected.

Procedure:

1. 1. 1. A vacuum box (usually made of transparent or translucent material) is placed over the weld or area to be tested.
      2. A vacuum pump is used to create a vacuum within the box.
      3. A pressure gauge or a pressure differential measurement device is used to monitor changes in pressure within the vacuum box.
      4. If there are leaks or defects, air will be drawn into the vacuum box, causing a pressure increase that can be detected.

Vacuum Tube Method:

Principle:

The vacuum tube method is similar to the vacuum box method but uses a tube or hose to apply the vacuum directly to the area of interest. It is often used for testing larger or more complex structures.

Procedure:

1. 1. 1. A vacuum tube or hose is connected to the area to be tested, typically at the lowest point of the structure.
      2. A vacuum pump is used to create a vacuum within the tube, which, in turn, applies the vacuum to the area of interest.
      3. Changes in pressure within the tube or hose are monitored, and any pressure increase suggests a potential leak.

Both methods are applicable for finding leaks, but the choice between them may depend on the specific circumstances, size of the structure, and accessibility of the area to be tested. It’s important to note that these methods require proper training and equipment to ensure safety and accurate results. Additionally, the sensitivity of leak detection and the test procedure may vary depending on the specific application and standards or regulations governing the testing process. Always follow the recommended guidelines and procedures for your particular situation.