What are the characteristics of pneumatic flap valves

What are the characteristics of pneumatic flap valves

Pneumatic flap valve (also known as pneumatic discharge valve, pneumatic air lock valve) is a key equipment for controlling the transportation and discharge of solid particles, dust and other materials in the industrial industry. Its core features are pneumatic drive, structural design, and functional adaptability, which can be divided into the following categories, including extended explanations of applicable scenarios and precautions:

Core driving and control features: fast response, easy operation.

Pneumatic drive, stable power

Relying on compressed air as a power source, it is particularly suitable for dusty, flammable and explosive working conditions (such as mining, chemical, and grain processing), to avoid safety risks caused by electrical component short circuits or sparks.

The driving pressure is usually 0.4-0.6MPa, which meets most industrial low-pressure gas source scenarios, and the cylinder output is stable. Materials with different densities (such as light dust and heavy particles) can be fine tuned for discharge strength by adjusting the gas source pressure.

Appropriate response speed and flexible control

The action delay of pneumatic systems is much lower than that of electric or hydraulic drives, and the valve opening and closing time can generally be controlled within 0.5-2 seconds (adjusted according to the diameter), which can respond to the "start stop" command of material conveying at a suitable speed, reducing material accumulation or leakage.

Support multiple control methods: manual buttons, PLC automatic control, remote signal linkage (such as linkage with upstream bin level gauge, automatic unloading when full, automatic valve closure when empty), to meet the needs of automated production lines.

Structure and sealing characteristics: leak proof, wear-resistant (based on actual reports) (based on actual reports).

Excellent air lock performance, reducing energy loss.

Its core function is to achieve "dynamic sealing" through a double flap (or single flap) sealing weight structure for "unloading": when the material falls, the pressure flap opens, and after unloading, the flap automatically resets under the action of the cylinder or weight, closely adhering to the valve seat, which can prevent airflow backflow in the pipeline (such as in pneumatic conveying systems, avoiding high-pressure air leakage from the discharge port, protecting stable conveying pressure, and reducing fan energy consumption).

Some models will install wear-resistant (based on actual reports) rubber ring sealing layers at the valve seat, which can control the air leakage rate below 1%, far better than ordinary electric gate valves.

Simple structure and easy maintenance

The main body consists of a valve body, a flap (valve plate), and is composed of a cylinder, solenoid valve, and seals. There are no complex transmission components (such as gears and worm gears), and there are few fault points. Daily maintenance only requires regular inspection of the wear of seals, cleaning of residues inside valves, and adding lubricating grease to cylinders, resulting in low maintenance costs and short downtime.

Flip plates are often made of Q235 carbon steel, stainless steel (304/316), or wear-resistant (based on actual reports) cast iron materials. Depending on the corrosiveness of the material (such as chemical acid and alkali dust) and the choice of wear (such as ore particles), the service life can be extended.

Function and adaptation characteristics: Strong universality and adaptability to complex working conditions.

Adapt to various materials and working conditions

Wide range of applicable materials: By adjusting the flipping angle and valve body diameter (commonly DN100-DN800), from fine dust particles with a particle size of 0.1mm (such as cement and flour) to coarse particles with a particle size of 50mm (such as ore and coal);

Wide temperature resistance range: General models can withstand -20 ℃ -150 ℃, high-temperature customized models (using high-temperature resistant (based on actual reports) seals and cylinders can withstand 300 ℃ -500 ℃ (such as boiler ash discharge), low-temperature models can be suitable for cold chain materials below -40 ℃ (such as frozen pellet feed).

Uniform unloading and anti blocking material design

The opening angle of the flap can be adjusted by the cylinder stroke (usually 0-90 °) to control the material unloading speed and avoid overloading downstream conveying equipment (such as screw conveyors) due to "instantaneous unloading too much";

The interior of the valve body is often designed with streamlined cavities, without right angles or dead corners, reducing the accumulation and bridging of materials inside the valve (especially viscous materials such as wet coal and clay). Some models can also be equipped with "arch breaking devices" (such as pneumatic hammers) to further prevent blockages.

Limitations (characteristics to be noted)

Dependent on compressed air system: If there is no stable air source on site, additional air compressors and storage tanks need to be configured to increase initial investment;

Not suitable for high viscosity/fiber materials such as plastic pellets and cotton wool, which are prone to entangling the flip shaft and causing sealing failure or valve jamming;

Antifreeze treatment is required at low temperatures: Moisture in compressed air is prone to freezing at low temperatures, which may clog cylinders or solenoid valves, requiring the installation of dryers or electric heat tracing devices.

What are the characteristics of pneumatic flap valves