Company News

hydraulic tubes, sealing test, test method

Company News

hydraulic tubes, sealing test, test method
Back to Results   |You are in :  Home  >  News  >  Company News

How To Test The Sealing of Hydraulic Tubes?

Date:2025-01-22View:140Tags:hydraulic tubes, sealing test, test method

There are many ways to test the tightness of hydraulic tubes. The following are some common test methods and specific operations:

 

Pressure test method

1. Test preparation

Install the hydraulic tube on the test bench and connect relevant test equipment, such as pressure pump, pressure gauge, etc. Make sure that the test system is firmly connected to the hydraulic tube without leakage risk. According to the working pressure range of the hydraulic tube, select a pressure gauge and pressure pump with a suitable range. Generally, the pressure gauge range should be 1.5-2 times the test pressure.

 

2. Test steps

Start the pressure pump and slowly fill the hydraulic tube with pressure medium (usually hydraulic oil or water) to gradually increase the pressure to the specified test pressure. During the pressure increase process, observe whether there is leakage in the hydraulic tube and each connection. After reaching the test pressure, keep the pressure stable for a period of time, usually 10-15 minutes, and pay close attention to the changes in the pressure gauge reading during this period. If the pressure drops by more than the specified value, it means that there is a sealing problem with the hydraulic tube.

 

3. Judgment criteria

Generally speaking, during the pressure maintenance period, the pressure drop should not exceed 5% of the test pressure. If it exceeds this range, the hydraulic tube needs to be inspected, the leak point needs to be found and repaired.

 

Bubble test method

1. Test preparation

Close one end of the hydraulic tube and connect the other end to the air source, such as a compressed air bottle. Prepare a basin of water or other suitable liquid to observe the bubble generation.

 

2. Test steps

Open the air source and slowly fill the hydraulic tube with a certain pressure of air, generally 0.3 - 0.5MPa. Immerse the hydraulic tube in water and carefully observe whether there are bubbles on the surface and connection parts of the hydraulic tube. If bubbles are generated, it indicates that there is a leak in that part.

 

3. Judgment criteria

If continuous bubbles are found during the test, regardless of the size of the bubbles, it means that the hydraulic tube is not sealed. The leaking part needs to be marked for subsequent repair.

 

Applying test fluid method

1. Test preparation

Prepare special sealing test fluid, such as soapy water, leak detection agent, etc., as well as application tools, such as brushes or sprayers.

 

2. Test steps

Apply or spray the test liquid evenly on the surface and connection parts of the hydraulic tube to ensure that all possible leaking parts are covered. Observe the part after applying the test liquid to see if there are bubbles or flow marks of the test liquid. If bubbles appear or the test liquid has obvious signs of flow, it means that there is a leak in this part.

 

3. Judgment criteria

The judgment is based on whether there are bubbles or abnormal flow of the test liquid. As long as the above phenomenon occurs, it means that there is a sealing problem in the hydraulic tube and it needs to be repaired.

 

Helium mass spectrometer leak detection method

1. Test preparation

A professional helium mass spectrometer leak detector and supporting equipment are required to place the hydraulic tube in a sealed test cavity to ensure that the cavity is well sealed.

 

2. Test steps

Fill a certain amount of helium into the hydraulic tube, and then scan and detect the test cavity with a helium mass spectrometer leak detector. The helium mass spectrometer leak detector can detect extremely small amounts of helium leakage, and judge the sealing of the hydraulic tube by detecting the amount of helium leakage.

 

3. Judgment criteria

According to the test results of the helium mass spectrometer leak detector, if the detected helium leakage exceeds the specified allowable leakage rate, the hydraulic tube is judged to be unsealed. Generally, for high-precision hydraulic systems, the allowable helium leakage rate is very low, usually below 10⁻⁹Pa・m³/s.

 

Summary

Pressure testing, bubble testing, smearing detection fluid, helium mass spectrometer leak detection and other methods have their own advantages and disadvantages. In practice, it is necessary to reasonably select the test method according to the use scenario, accuracy and budget of the hydraulic tube to ensure its sealing and ensure the stable operation of the hydraulic system.