Discharge Gate Rubber Seal

Function

The rubber seal absorbs gate closure impact — actuators typically close in under one second — while maintaining a continuous compression seal for the full mixing cycle (typically 30–60 seconds per batch). It also damps the acoustic shock of gate closure, reducing fatigue on the gate frame bolts. Seal degradation is accelerated by abrasive fines, ozone exposure, hydraulic oil contact, and thermal cycling. Replacement at the first sign of leakage avoids the higher cost of haul-away and reprocessing of off-specification material.

Construction & quality

Moulded from 70 Shore A EPDM compound for superior ozone and weathering resistance in tropical and arid climates. Cross-section is either a hollow-bulb D-section for low-closure-force pneumatic gates or a solid P-section for heavy hydraulic gates. Moulded to the exact perimeter profile and corner radius of the gate frame using multi-cavity tooling; corner joints are vulcanised at moulding, not adhesive-spliced. Dimensional tolerance on section width: ±0.5 mm. Outer retaining lip is ribbed for positive channel engagement. Natural rubber (NR) compound is available as an alternative where gate operating temperatures remain below 60 °C.

When to replace

• Visible wet mix leaking at the gate perimeter during the mixing cycle
• Rubber surface showing ozone crazing, surface cracks, or permanent hardening
• Cross-section depth reduced more than 30% from new measurement
• Sections that do not recover their original profile after the gate opens
• Gate actuator operating pressure increased to maintain a closed position