Avoiding installation mistakes is critical to preventing premature seal failure, leakage, and equipment damage. The key is to eliminate errors in preparation, precision alignment, and operational checks.
Below are the 8 most common mistakes and how to avoid them:
1. Skipping Compatibility and Condition Checks
- Mistake: Installing the seal without verifying if its model, size, and material match the equipment’s temperature, pressure, and medium. Also ignoring pre-installation inspections for seal defects (e.g., cracked faces, deformed O-rings) or shaft/chamber damage (e.g., scratches, burrs).
- Avoidance: Always cross-check the seal’s specifications against the application requirements. Inspect all components (seal, shaft, chamber) for damage before installation.
2. Poor Cleanliness Leading to Contamination
- Mistake: Allowing dirt, metal shavings, or residual media to remain on the seal faces, shaft, or seal chamber. Even tiny particles can scratch the sealing interface or cause binding.
- Avoidance: Clean all parts with a lint-free cloth and compatible solvents (non-corrosive to seal materials). Ensure the installation area is dust-free.
3. Ignoring Coaxiality and Shaft Runout
- Mistake: Failing to check the shaft’s runout (eccentricity) at the seal position. Excessive runout (beyond the seal’s limit, usually ≤0.1mm) causes uneven face wear and leakage.
- Avoidance: Use a dial indicator to measure shaft runout. If it exceeds the limit, repair or replace the shaft before installing the seal.
4. Incorrect Seal Compression
- Mistake: Over-compressing (causes excessive friction and heat) or under-compressing (fails to form a tight seal) the seal’s elastic components (O-rings, springs). This is often due to not following the manufacturer’s torque or gap guidelines.
- Avoidance: Strictly adhere to the manufacturer’s instructions for compression. For cartridge seals, remove setting clips only after final tightening.
5. Uneven Gland Bolt Tightening
- Mistake: Tightening gland bolts in a random order (not crisscross) or with uneven torque. This distorts the seal chamber, misaligns the seal faces, and breaks the sealing interface.
- Avoidance: Use a torque wrench and tighten bolts in a crisscross pattern (e.g., 1-3-2-4 for 4 bolts) to apply uniform pressure. Follow the recommended torque value.
6. Tilting or Misaligning Seal Faces
- Mistake: Installing component seals with the stationary and rotating faces tilted (not parallel) or misaligned. This destroys the thin lubricating film between the faces, leading to dry friction and rapid wear.
- Avoidance: When assembling component seals, ensure faces are perfectly parallel. Use alignment tools if needed, and avoid forcing the seal into place.
7. Forgetting Post-Installation Manual Rotation
- Mistake: Starting the equipment immediately after installation without manually rotating the shaft. Binding or tight spots (caused by misalignment or debris) can damage the seal once the machine runs.
- Avoidance: Manually rotate the shaft 2-3 full turns after installation. It should feel smooth—if there’s resistance, disassemble and recheck.
8. Rushing Startup Without Leakage/Temperature Checks
- Mistake: Starting the equipment at full speed right away and not monitoring initial performance. Immediate leakage or overheating (seal face temp >80°C for standard seals) can go unnoticed, leading to severe failure.
- Avoidance: Start the machine at low speed first, then gradually increase to normal. Monitor for leakage (no visible drops) and face temperature. Stop immediately if issues arise.
