Seal Replacement Guide for Air-Jet Valves
Key Takeaway: Standard Viton seals: replace every 500,000 cycles or 6 months. High-temperature Kalrez seals: every 300,000 cycles or 4 months. Aggressive resins (PVC, FR compounds): every 150,000 cycles or 2 months.
Replacement Intervals by Condition
| Operating Condition | Seal Material | Replacement Interval |
|---|---|---|
| Standard (≤150°C, clean air) | Viton (FKM) | 500,000 cycles / 6 months |
| Elevated temp (150–200°C) | Viton (FKM) | 200,000 cycles / 3 months |
| High temp (200–300°C) | Kalrez (FFKM) | 300,000 cycles / 4 months |
| Aggressive resins | Viton or Kalrez | 150,000 cycles / 2 months |
Seal Replacement Procedure
- Remove the valve from the mold bore (use a valve extraction tool or soft-jaw pliers).
- Inspect the bore for scoring or damage. Clean with solvent.
- Remove old O-rings and poppet seal. Inspect the valve body for resin contamination.
- Install new seals (lubricate with silicone grease). Ensure O-rings are seated in their grooves without twisting.
- Re-install the valve. Test poppet movement and air blast strength.