What Is an Airlock Valve and How Does It Work? A Complete Beginner’s Guide

Summary

An airlock valve is a critical component in bulk material handling and pneumatic conveying systems. It is widely used to control the flow of powders and granules while maintaining a pressure seal between different parts of a system.

For engineers, plant operators, and buyers, understanding how an airlock valve works is essential for ensuring system efficiency, preventing air leakage, and maintaining stable material flow.

In this guide, we explain what an airlock valve is, how it works, its main applications, and how to choose the right type for your industrial system.

What Is an Airlock Valve

An airlock valve, also known as a rotary airlock valve or rotary feeder, is a mechanical device used to transfer bulk materials between areas of different pressure while minimizing air leakage.

Main Functions:

• Control material flow
• Maintain pressure difference
• Prevent air leakage
• Ensure continuous feeding

Airlock valves are commonly used in industries such as:

• Cement
• Food processing
• Chemical
• Pharmaceutical

How Does an Airlock Valve Work

Basic Working Principle

An airlock valve operates using a rotating rotor with multiple pockets.

Step-by-Step Process:

1. Material Enters the Valve

Bulk material (powder or granules) flows into the inlet of the valve from a hopper or silo.

2. Rotor Captures Material

The rotating rotor has compartments (pockets) that collect the material.

3. Rotation Transfers Material

As the rotor turns:

• The material is carried inside the pockets
• It moves from the inlet to the outlet

4. Airlock Function Is Maintained

During rotation:

• The valve isolates high-pressure and low-pressure zones
• Prevents air from flowing backward

5. Material Is Discharged

At the outlet:

• Material is released into the next stage
• Usually into a pneumatic conveying line