5 Things to consider when selecting a Rotary Airlock Valve

selecting a Rotary Airlock Valve

Choosing the right rotary airlock valve is key to keeping your industrial processes safe and efficient. Every industry has its unique needs based on the products it handles, so it’s essential to select the appropriate valve. To assist you in making an informed decision, our blog explains the five essential considerations to keep in mind when choosing a rotary airlock valve. By understanding these key points, you can confidently select a rotary airlock valve that aligns with your specific needs, improving the overall reliability and productivity of your operations.

How Does Rotary Airlock Valve Work?


When the valve is running, the vane rotor spins inside the housing, working similarly to a revolving door. The key purpose is to allow a controlled flow of material while preventing air/gas from escaping, just like a revolving door controls the movement of people while keeping inside and outside environments separated.

Material Pockets

The spaces between the spinning vane blades form little pockets. Material enters through the top opening and sits in these pockets temporarily before being pushed out the bottom opening to continue along the pneumatic conveying lines.

Pressure Isolation

There is very little gap between the spinning vane tips and the housing interior. This small clearance minimizes air/gas leakage from the system. This is important when you have different pressure levels between equipment like bins, silos, hoppers, and the next part of the process. Installing airlocks at pressure/vacuum transition points helps maintain the proper pressure separations.

selecting a Rotary Airlock Valve

What Are The Top 5 Things To Consider When Choosing A Rotary Airlock Valve?

  • Valve Type: 

It’s really important to know exactly what kind of rotary airlock valve you need based on the product you’re handling and the process it will go through. Airlock valves are designed to separate the product while dealing with differences in pressure between the inlet and outlet sides. So choosing the right valve type is crucial for efficiently and safely transferring your powdered or granular materials.

  • Size Matters: 

The size of your rotary airlock valve plays a significant role in determining your production capacity. It’s essentially a matter of matching the valve’s volumetric capacity to the desired flow rate of your product. You need to calculate the ideal rotation speed for the rotor, keeping in mind the maximum speed the valve can handle. Getting the size right ensures that your valve can keep up with your production demands without any bottlenecks.

  • Product Nature: 

Think of your product as having its own personality. Some products are easygoing and flow smoothly, while others might be sticky, abrasive, or prone to clumping.  These characteristics can significantly impact the valve’s performance. Before you select a rotary airlock valve, carefully consider your product’s properties – its density, flowability, particle size, and any other relevant factors. This will help you select a valve with the right materials and design to handle your specific product without any issues.

  • Pressure Ratings: 

Rotary airlock valves operate based on a pressure differential between the inlet and outlet sides. Therefore, it’s essential to choose a valve with a pressure rating that matches or exceeds the pressures present in your system. High-pressure applications require robust valves that can withstand the force without leaking or failing. A good quality valve will also have a venting system to prevent pressure buildup and ensure safe operation.

  • Temperature Tolerances: 

Temperature can significantly impact the performance and longevity of a rotary airlock valve. The materials used in the valve’s construction need to be able to handle the temperature fluctuations in your process. Whether you’re dealing with extreme heat or cold, choosing a valve with appropriate temperature tolerances is crucial to prevent warping, cracking, or other damage that could compromise its functionality.

  • Size Matters: 

The amount of product that can flow through depends on the rotary valve’s volumetric capacity and how fast the rotor spins. You need to estimate the ideal rotation speed, taking into account the maximum speed limit. Getting the valve size right ensures your production rates can be properly handled.

  • Product Nature: 

You must select a rotary airlock valve that is a good fit for the specific product you’ll be transferring. The nature and characteristics of the material should not interfere with or reduce the valve’s performance. Before choosing, understand your product in-depth – its behaviors, any potential issues, and what maintenance might be needed.

  • Pressure Ratings: 

Since rotary valves work by differential pressure between the inlet and outlet, you need a valve rated for the pressure ranges in your system. If you’re dealing with very high pressures, the valve has to be super durable and built strong enough to withstand it safely. It should also have a reliable venting system to prevent any leaks. High-pressure systems require robust, high-performance airlock valves.

  • Temperature Tolerances: 

Temperature is another important factor. Think about the potential temperature ranges in your process – how hot or cold it might get. This will determine what materials the rotary valve needs to be constructed from so it can withstand the temps without failure. Know your product and process temperatures from start to finish when specifying the airlock valve.

Types Of Rotary Airlock Valve

The top types of rotary airlock valves include:

Fall-Through Rotary Valves:

  • In these types of rotary airlock valves, the material simply drops straight through the valve from the top inlet to the bottom outlet.
  • These are suitable when the material flow is gravity-fed and just needs to pass directly through the valve.

Blow-Through/Conveying Rotary Valves:

  • Also called “pneumatic” rotary valves.
  • Designed specifically for pneumatic conveying systems where an air/gas stream is used.
  • The airflow blows/conveys the material through the valve’s inlet and outlet.

Standard Duty Rotary Valves:

  • The general-purpose, basic model used for typical industrial applications.
  • Handles standard pressure differences and typical material characteristics.

Heavy Duty Rotary Valves:

  • Built with a more robust, heavy-duty construction.
  • Meant for handling abrasive or challenging materials that cause extra wear.
  • Can withstand demanding conditions and tough environments.

Quick-Clean Rotary Valves:

  • Feature a design that allows for easy disassembly and thorough cleaning.
  • Well-suited for industries like food, pharmaceutical, etc. where frequent cleaning is required.

Dust Collector Rotary Valves:

  • Specifically used as part of dust collection systems.
  • Helps maintain an air-tight seal to prevent dust from escaping the collection equipment.

The seals used in rotary airlock valves also vary:

Flexible Rubber Seals:

  • Soft, pliable rubber seals that conform to rotor/housing surfaces.
  • Provide an effective air-tight seal for general applications.

Neoprene Seals:

  • Made from a synthetic rubber known for durability and abrasion resistance.
  • Well-suited for applications with abrasive materials.

Nitrile (Buna-N) Seals:

  • Nitrile rubber seals offer good oil/grease resistance and flexibility.
  • Used where exposure to oils/lubricants is expected.

Polyurethane Seals:

  • Polyurethane provides high abrasion resistance and wear life.
  • Ideal for abrasive materials requiring extended seal durability.

Metal-to-Metal Seals:

  • Used in high temperature or extreme pressure conditions.
  • Constructed of metal for maximum strength and resilience.


Selecting the right rotary airlock valve is crucial for efficient and safe material handling in your operation.  By evaluating these top considerations, you can find the perfect rotary valve solution to reliably transfer materials while maintaining proper pressures and preventing leakage. If you need any assistance, Trimech India has experts who can guide you in choosing the airlock valve that optimally meets all your operational requirements. Don’t hesitate to reach out to make sure you get the ideal valve for years of dependable service.


Q: What are the main factors to consider when selecting a rotary airlock valve? 

A: The key factors are types of rotary airlock valves, size, material characteristics, pressure rating, and temperature tolerances.

Q: How do the types of rotary airlock valves differ from each other?

 A: The main types like fall-through, blow-through/conveying, standard, heavy-duty, quick-clean, and dust collector valves are designed for different applications.

Q: Why is choosing the right rotary airlock valve size important? 

A: Proper valve sizing based on material flow rates ensures production rates can be handled efficiently.

Q: What role do seals play in rotary airlock valves? 

A: Seals like rubber, neoprene, nitrile, polyurethane, or metal provide an airtight seal to separate pressure zones.

Quick Contact Us
We welcome any feedback, questions or comments