Mechanical seal leakage
Thread Content
This post was last edited by SHISHOUHUA on 2009-9-5 08:16. Yesterday, the pump was overhauled and a new seal was installed; after installation, there was no leakage when the inlet valve was opened. However, leakage started to occur once the pump was started up. I wonder if anyone knows the reason for this.
The interface isn’t good, check the interface area. Static and dynamic are different
The compression amount of the mechanical seal is low; open it and measure the compression amount of the mechanical seal.
It’s also possible that there is a problem with the machine seal; the pressure is low when the pump is at rest, but it becomes high once the pump starts operating
If no leakage occurs when the inlet valve is opened, it indicates that the static seal of the mechanical seal is in good condition; if leakage occurs, it means there is a leak at the contact surface between the stationary and rotating rings. There are two possible reasons for this: 1. Improper installation – disassemble it and reinstall it carefully. 2. If the spring preload is too low, there are usually indentations from the fixing bolts left over from the installation of the old seal on the shaft; pre-tighten it according to the original position! 3. Once the answer is submitted, wait for the points to be added!
It’s likely that the compression level is too low; it’s recommended to adjust it
It’s very likely that it wasn’t installed properly, with some deviation. Take it off and reinstall it carefully ； The situation described by the poster is likely due to a leak at the contact surface between the rotating ring and the stationary ring; it is also necessary to check whether there are any scratches or debris on these rings. Please conduct a thorough inspection. Thank you!!!
If the leakage is minimal and returns to normal after operating for a while, but if the leakage is severe and the compression volume is low, the compression volume should be adjusted.
It’s very likely that it wasn’t installed properly! It is recommended to adjust the mechanical seal
I agree with what was said above; it seems that the compression amount is too low. You can check this by removing the pump, taking off the nut that holds the impeller in place, and positioning the pump vertically. Then press down on the impeller to see if it has any elasticity up and down. If there is no elasticity or very little, then it’s indeed a problem related to the low compression amount. It’s easy to fix. Don’t remove the mechanical seal entirely, or remove only one side of it. If it’s a spring-type seal, you can lower the moving ring a bit; if it has a seat, you can add a washer under either the moving ring or the stationary ring. If the pump starts rotating, remove just one side of the mechanical seal – this way, the seal is less likely to leak