Weighted Air Lock Flap Valve

Weighted Air Lock Flap Valve, also known as counterweight flap airlock, is a widely used passive sealing and discharging equipment. Driven by material gravity and counterweight torque, it needs no external power such as motor or air cylinder. The valve is mainly installed under silos, dust collectors, cyclones and conveying pipelines to discharge powder, granules and bulk materials, while effectively isolating pressure difference and preventing air leakage, gas backflow and material channeling. Both single flap and double flap designs are available to meet different air tightness requirements.

Main Structure

Integrated Steel Body: Sturdy welded structure with standard flanges at both ends for easy pipeline connection. The streamlined inner cavity avoids material buildup and clogging.

Sealing Flap Plate: Equipped with durable elastic gaskets, which fits closely with the valve seat to ensure excellent sealing performance.

Adjustable Counterweight Mechanism: External lever and weighted block can be freely adjusted to change the opening pressure of the flap, adapting to various materials and flow rates.

Rotating Shaft & Bushing: Adopts wear-resistant and high-temperature resistant materials, featuring flexible rotation, low friction and long service life.

Working Principle

When materials fall and accumulate on the flap plate, their gravity gradually overcomes the tension of the counterweight. The flap opens automatically to discharge materials. Once the materials are emptied, the counterweight pulls the flap back to its original position quickly and forms a tight seal again.

For double flap type, the upper and lower flaps work in alternating opening and closing state. One flap always remains closed during operation, which thoroughly cuts off the air flow between upstream and downstream and realizes zero air leakage.

Key Features & Advantages

Energy Saving & Easy Installation: Fully gravity-driven, no extra power consumption, simple structure and convenient on-site installation.

Reliable Air Locking: Greatly blocks air infiltration under negative pressure and gas overflow under positive pressure, keeping the whole system pressure stable.

Strong Adaptability: Suitable for dry powder, particles and small bulk materials; works well under normal temperature, high temperature and abrasive working conditions.

Anti-blocking Design: Smooth internal structure effectively prevents material bridging and jamming.

Low Maintenance: Few vulnerable parts. Only regular inspection of gaskets and slight adjustment of counterweight are needed for long-term operation.

Application Range

It is widely applied in environmental protection dust removal, thermal power, cement, metallurgy, chemical industry, grain processing and other industries. It is an essential accessory for material conveying and dust collecting systems.