212 Single-face Mechanical Seal

Mechanical seals are categorized into single-face 212 mechanical seals and single-face 204B mechanical seals.

Before installation, verify the following aspects:

1. Confirm sufficient installation space and dimensional requirements at the sealing location.

2. Ensure the technical parameters of the installed mechanical seal match the equipment's operating parameters.

3. Upon confirming the above conditions, perform the following tasks:

Mechanical Seal Installation

1. Place the mechanical seal in a clean environment, taking care not to damage the dynamic seal rings or static seal gaskets.

2. Verify that the seal ring material is compatible with the sealing medium.

3. Ensure all screws pass through the locking ring and shaft sleeve without protruding beyond the inner shaft wall.

4. When installing, reinstalling, or removing the seal, confirm all locating blocks and hex screws are present.

5. Slide the entire mechanical seal assembly onto the shaft. Apply lubricant where the shaft passes through the O-ring to ensure smooth, gradual descent. Verify:  

  A. Proper contact between the mechanical seal's static sealing face and the equipment's sealing surface.    

  B. Alignment of the mechanical seal's sealant/coolant ports with the equipment's external sealant/coolant/flushing fluid pipe connections.    

  C. Alignment of the mechanical seal gland cover bolt holes with the equipment bolts to center the gland cover.

6. Tighten the gland bolts evenly. Tightening the gland bolts must precede tightening any locking screws.

7. Use a hex wrench to evenly tighten the locking screws on the retaining ring, securing the mechanical seal to the shaft. If tightening requires rotating the shaft, one locating block may be loosened or removed provided it does not alter the seal's installation dimensions.

8. Remove the positioning block and its securing screws; store them securely (for future maintenance).

9. Verifying concentricity between the gland and shaft sleeve is critical. Rotate the shaft to confirm free movement. If metallic contact sounds are heard within the seal, this indicates misalignment. Reinstall the positioning block, loosen the gland bolts, and release the locking screws. Re-tighten the gland cover and screws. Remove the locating block. If the metallic clanging persists, inspect the concentricity between the seal chamber and the shaft.

10. For dry-running mechanical seals, verify the lubricant saturation level in the seal chamber. It is recommended to inject lubricant into the seal chamber monthly. For sanitary applications, medical-grade petroleum jelly may be used.

11. Before startup, implement all necessary precautions and follow standard safety procedures. If the mechanical seal is disassembled for maintenance of other host components (with the seal itself undamaged), it must undergo re-grinding, polishing, and other maintenance procedures before reassembly and reuse.

12. Water cooling is required when temperatures reach 80°C.

13. Radial runout of the shaft at the seal installation point:
   - For glass-lined vessels:
   - When shaft diameter D < 110 mm: Runout < D/30
   - When shaft diameter D > 110 mm: Runout < 0.5 mm
   - Axial play < 0.5 mm
   - For metal vessels: Radial runout < 0.2 mm

14. Coaxiality between locating flange and shaft: <0.2 mm; perpendicularity: <0.1 mm.

15. When rotational speed exceeds 150 RPM, use variable frequency drive for gradual startup.

(All cartridge mechanical seals undergo static air pressure testing at 8 kg/cm² for 20 minutes and are shipped only after passing inspection.)