Counterweight Flap Valve (Lock‑Air Discharge Valve)
Counterweight Flap Valve (also known as lock‑air flap valve or counterweight ash discharge valve) is a purely mechanical, non‑electric device for automatic material discharge + airtight sealing. It opens by material weight and resets via a counterweight lever, widely used under dust collector hoppers, silos and mills to prevent air leakage, backflow and ensure reliable sealing.
1. Main Structure
Body: Carbon steel/stainless steel welded, square/round flanged connections.
Flap (Disc): Single/double layer (double layer standard), wear‑resistant sealing surface.
Counterweight Lever System: Weighted arm + adjustable counterweight, automatic reset with adjustable torque.
Seals: Beveled sealing face + soft gasket, air leakage rate ≤2%.
Shaft & Bearings: Low‑friction rotation, maintenance‑free, no jamming.
2. Working Principle (Double‑Layer Typical)
Upper flap: Material accumulates to a set weight → automatically opens, material falls to lower layer;
Upper counterweight reset: Material discharged → counterweight lever closes upper flap airtight;
Lower flap: Repeats above, alternating open/close for continuous discharge;
Full‑time lock‑air: Double‑layer interlaced seal, prevents external air backflow, maintains system negative pressure.
3. Technical Parameters (Standard)
Model: ZJSXF‑I (Single‑layer) / ZJSXF‑II (Double‑layer)
Size: Square 150×150～800×800mm; Round DN150～DN800
Drive: Pure mechanical counterweight (no motor)
Temperature: ≤150℃ (standard); ≤300℃ (high‑temp)
Media: Dry dust, granules, small lumps (ash, coal powder, grain, fertilizer)
Capacity: 5～300m³/h (adjustable)
Air Leakage: ≤2% (double‑layer)
4. Core Advantages
No Power, Energy‑Saving & Reliable: Pure mechanical, no motor/energy consumption; safe for power‑off/explosion‑proof areas.
Double‑Layer Seal, Efficient Lock‑Air: Interlaced seal, prevents backflow, maintains negative pressure, no impact on dust collection/conveying efficiency.
Wear‑Resistant & Low Maintenance: Welded steel + wear‑resistant flap, no complex transmission; long life, few failures, maintenance‑free.
Automatic Discharge, Easy Adjustment: Adjustable counterweight position, adapts to different material weights/pressures; automatic start/stop, no labor.
Wide Application, Flexible Installation: Carbon steel/stainless steel options, square/round connections; fits dust collectors, silos, mills, dryers.
5. Applications
Dust Collection: Baghouse/ESP/composite collector hopper discharge & lock‑air.
Building Materials & Cement: Kiln tail, mill, dryer silo discharge.
Metallurgy & Steel: Sintering machine, blast furnace hopper, dust conveying.
Power & Thermal Power: Boiler hopper, fly ash conveying system.
Chemical/Grain: Powder/granule silo bottom discharge, air leakage prevention。
