Three methods of vacuum leak detection

1. The advantages and disadvantages of using the irrigation method to search for vacuum systems that are not tight

The vacuum system contains a large number of equipment and systems, and there are many dynamic and static sealing points connected. It is difficult to detect the leakage point in the case of slight air leakage because the air is sucked in, which is not intuitive enough. The traditional flame inspection method used in operation is cumbersome and ineffective. In most cases, the method used is to fill the vacuum system with water to find the leakage after the unit is shut down.

This method is relatively intuitive, and leakage points are easily detected. The disadvantage is that due to equipment reasons, the highest filling height can only reach the lowest shaft seal groove of the cylinder, and the places higher than the shaft seal groove are difficult to detect because they cannot be removed from the water, especially the pipeline system connected to the steam turbine cylinder.

2. Advantages and disadvantages of using helium mass spectrometry to search for methods that are not tight in vacuum systems

The use of helium mass spectrometry method usually involves injecting helium gas at a suspicious point and then detecting it at the vacuum pump end to see if helium gas can be detected. If helium gas is detected, it indicates a leak at this suspicious point.

This method can determine the general location of the leak and have a relative value data. But the use of the equipment is more labor-intensive and requires three to four people to operate; The helium mass spectrometry method is greatly affected by the environment, and moderate air mobility can cause trouble in determining the leak point; In addition, it is difficult to use helium mass spectrometry for leak detection on air-cooled islands. It is difficult to determine the leakage point in locations with many pipelines.

3. Advantages and disadvantages of using ultrasound to find methods that are not tight in vacuum systems

Ultrasonic leak detection method is a convenient and fast method, which is easy to operate and can be operated by one person; And it can accurately determine the location of the leakage point, making it more convenient to plug the leak; It is more convenient, fast, and accurate to apply on air-cooled islands. The disadvantage is that certain operating experience is required when using.