HM Mechanical Seal Installation, Operation Instructions and Precautions

HM Mechanical Seal Installation, Operation Instructions and Precautions

1. Before installation, ensure that the shaft (or shaft sleeve) and gland are free of burrs. The shaft surface roughness must be no less than Ra1.6, the shaft outer diameter tolerance should be h6, and the surface roughness should be Ra 1.6–3.2 µm or better.

2. Check the axial float and radial runout of the shaft at the mechanical seal installation location: the axial float should not exceed 0.12 mm, and the radial runout tolerance at the stationary ring location should not exceed 0.04 mm.

3. Check whether the sealing face is perpendicular to the shaft axis. Ensure that the deviation from perpendicularity is less than 0.05 mm.

4. The end of the shaft where the mechanical seal is to be installed must have a chamfer of 1.5–3 mm × 20º, with a smooth transition at the sharp corner.

5. Remove the mechanical seal product from its packaging box with care. Handle gently and avoid any impact or knocking. After removal, first check the compensation performance of the seal’s rotating ring by pressing both ends of the seal and observing whether it rebounds quickly and smoothly.

6. During installation, clean the shaft, seal cavity, sealing faces, and the mechanical seal itself thoroughly. Apply engine oil or soapy water to the friction faces of the rotating and stationary rings to prevent any impurities from entering the sealing area.

7. Do not use tools to strike the seal components during installation to avoid scratching the sealing faces of the rotating and stationary rings. When assembling the rotating ring, ensure it moves flexibly on the shaft with some float. When assembling the stationary ring, ensure it has some float within the gland and maintains a certain clearance from the shaft.

8. Pre-operation checks:
① Check that the auxiliary equipment, cooling, and lubrication systems for the mechanical seal are complete and unobstructed.
② Check the shaft rotation direction and whether the lubricating oil at the bearing location is adequate.
③ Perform cleaning to prevent rust or impurities from entering the seal cavity.
④ Verify that the shaft assembly dimensions are correct and that rotation is smooth.

9. Operation procedure:
① Normal-pressure operation: Before starting the main equipment, ensure the seal cavity is filled with liquid or the sealed medium (especially when the friction pair is made of hard materials). Check for minor leakage. A run-in period is allowed to ensure uniform contact of the sealing faces until leakage gradually decreases to a normal level (calculated leakage rate not exceeding 0.1 ml/h).
② Pressure and temperature increase operation: During the process of increasing pressure and temperature, check for any part collisions, separation of sealing faces, severe friction heating, or machine vibration. If everything is normal, the equipment can be put into formal operation.

Zhejiang Hongmi Technology Co., Ltd.
March 15, 2014