What Should Be Noted For The Mechanical Seal Of Submersible Sewage Pumps

Aug 14, 2025

1. Before operating any mechanical seal equipment for sewage pumps, carefully inspect whether the number of mechanical seal components meets requirements and check for any damage to the parts, especially scratches, cracks, or deformations on the dynamic and static rings. If issues are found, repair or replace the components.

2. Verify whether the chamfer of the shaft sleeve or gland is appropriate. If not, repair it as necessary.

3. Prior to operating the mechanical seal of a submersible sewage pump, thoroughly clean all seal components and their contact surfaces on related equipment. Maintain cleanliness during installation, ensuring no impurities or dust on the surfaces of the dynamic/static rings or auxiliary sealing elements. Apply a layer of clean machine oil or turbine oil to the surfaces of the dynamic and static rings.

4. To prevent gland face misalignment, after aligning the coupling, tighten the gland bolts evenly and check each point with a feeler gauge-deviation must not exceed 0.05 mm.

5. Use a feeler gauge to check the clearance (i.e., concentricity) between the gland and the shaft or shaft sleeve outer diameter. The clearance must be uniform around the circumference, with a maximum permissible deviation of 0.1 mm.

6. The spring compression must comply with specifications-excessive or insufficient compression is unacceptable, with a permissible deviation of ±2.00 mm. Excessive compression increases face pressure, accelerating wear, while insufficient compression fails to provide proper sealing. After installation, the spring should move freely within its seat. For single-spring installation, ensure the spring's winding direction is opposite to the shaft rotation.

7. When installing the dynamic ring, ensure it moves freely. After pressing it against the spring, it should rebound automatically.

8. For static ring installation, first fit the sealing ring onto the back of the static ring before placing it into the seal cover. The perpendicularity between the static ring face and the cover centerline must meet technical requirements. Align the anti-rotation groove on the static ring's back with the anti-rotation pin, but avoid direct contact. Take care not to damage the static ring face during installation.

9. Throughout installation, never strike seal components with tools to prevent damage.