Airlock Valve vs Rotary Valve: What’s the Difference and Which One Should You Choose?

Summary

Many industrial buyers use the terms airlock valve and rotary valve interchangeably. While the two products are closely related, they are not always exactly the same in function and application.

Understanding the differences between airlock valves and rotary valves is important for selecting the correct equipment for:

• Pneumatic conveying systems
• Dust collection systems
• Bulk material handling
• Pressure conveying applications

This guide explains the key differences, working principles, applications, advantages, and how to choose the right valve for your industrial system.

What Is a Rotary Valve

A rotary valve is a mechanical device used to:

• Feed bulk materials
• Control material flow
• Transfer powders and granules

How It Works

A rotating rotor with multiple pockets moves material from the inlet to the outlet continuously.

 Primarily designed for controlled material feeding

What Is an Airlock Valve

An airlock valve is a type of rotary valve specifically designed to:

• Maintain pressure difference
• Prevent air leakage
• Feed material into pneumatic conveying systems

How It Works

The rotor transfers material while maintaining an airtight seal between two pressure zones.

 Focused on pressure sealing performance

Main Difference Between Airlock Valve and Rotary Valve

All airlock valves are rotary valves, but not all rotary valves are true airlock valves

How Rotary Valves and Airlock Valves Work

Rotary Valve Operation

Main Purpose

• Metering material flow

Typical Use

• Gravity feeding systems

Airlock Valve Operation

Main Purpose

• Maintain pressure separation

Typical Use

• Pneumatic conveying systems
• Dust collection systems

Best Applications for Rotary Valves

• Bulk material feeding
• Powder discharge
• Metering applications
• Gravity-fed systems

Common Industries

• Agriculture
• Food processing
• Chemical industry

Best Applications for Airlock Valves

• Pneumatic conveying
• Dust collection systems
• Pressure conveying lines
• Vacuum conveying systems

Common Industries

• Cement
• Power plants
• Pharmaceutical
• Mining

Advantages of Rotary Valves

1. Simple Material Feeding

• Stable discharge rate

2. Compact Structure

• Easy installation

3. Cost-Effective

• Lower system cost

Advantages of Airlock Valves

1. Excellent Air Sealing

• Reduced pressure loss

2. Improved System Efficiency

• Stable airflow control

3. Reduced Dust Leakage

• Cleaner operation

4. Essential for Pneumatic Conveying

• Maintains conveying pressure

Airlock Valve vs Rotary Valve in Pneumatic Conveying

Rotary Valve

May work for low-pressure systems but can experience:

• Air leakage
• Reduced conveying efficiency

Airlock Valve

Designed specifically for:

• Pressure differential
• Air sealing
• Efficient conveying