Precautions for Installation of Mechanical Seals on Forced Circulation Pumps

Pre-installation Inspection 

1. Check the dimensional tolerance of pump shaft, shaft sleeve and seal chamber; eliminate burrs, scratches and corrosion on mating surfaces.

2. Clean all seal components thoroughly with clean solvent, no sundries, dust or particle residue on sealing faces.

3. Verify model, specification and material of mechanical seal conform to design requirements.

4. Inspect static ring, rotating ring sealing faces for crack, chipping and damage.

Mounting Requirements

1. Apply a thin layer of compatible lubricant on shaft surface before fitting the seal; avoid corrosive grease damaging elastomers.

2. Control the compression amount of spring precisely; excessive pre-compression leads to rapid wear of seal faces, insufficient compression causes leakage.

3. Keep coaxiality of shaft and seal cavity within specified tolerance to prevent eccentric abrasion during operation.

4. Install anti-rotation pin correctly to avoid static ring circumferential rotation.

5. Tighten gland bolts evenly in diagonal sequence to prevent gland deflection and seal face uneven stress.

Post-installation & Commissioning 安装后试车注意

1. Turn pump rotor manually after assembly; the shaft shall rotate flexibly without jamming or abnormal friction resistance.

2. Complete auxiliary flushing/quench piping connection per API Plan standard before startup.

3. Fill medium into pump cavity to ensure sealing surfaces get liquid lubrication; prohibit dry running of mechanical seal.

4. Carry out no-load test run first, monitor sealing part for dripping or abnormal heating.