The problem of the stainless steel filter's discharge outlet not closing may be due to the use of fluororubber sealing between the discharge end cover and the valve body to ensure sealing effectiveness. ‌‌

When designing the stainless steel filter, the sealing between the discharge end cover and the valve body adopts fluororubber sealing, which aims to ensure good sealing performance. The fluororubber sealing ring is embedded in the drain end cover, making it easy to quickly install the filter after cleaning. However, if it is found that the sewage outlet cannot be closed, possible reasons include:

1. Aging or damage of sealing ring: After long-term use, the fluororubber sealing ring may age or be damaged, leading to a decrease in sealing performance.

2. Improper installation: During the installation process, if the sealing ring is not installed correctly or the drain end cover is not fully closed, it can also cause the drain outlet to fail to close.

3. Impurity impact: Impurities or dirt may accumulate around the sewage outlet, affecting the sealing effect.

The methods to solve this problem may include:

1. Check and replace the sealing ring: If the sealing ring is found to be aged or damaged, a new fluororubber sealing ring should be replaced.

2. Reinstall the drain cover: Ensure that the drain cover is installed correctly and the sealing ring is in the correct position.

3. Clean the sewage outlet: Remove impurities and dirt around the sewage outlet to ensure that the sewage end cover can be tightly closed.

If the above methods still cannot solve the problem, it is recommended to contact professional maintenance personnel for inspection and repair to ensure that the filter can work properly.