Rotary Airlock Feeders

Rotary airlock feeders are a type of industrial valve used to process and transfer dry bulk materials for production. They’ll often be referred to as rotary valves, rotary airlocks, or just airlocks, and they are commonly used to transfer solid bulk materials (like powders, granules, and pellets, for example) from hoppers, bins or cyclones and into the vacuum and pressurized pneumatic conveying systems. 

The components of a rotary airlock feeder include the outer housing, rotor, shaft, end plates, drive, shaft packing seals, and bearings. 

Rotary airlock feeders are built with precision in mind, even if they’re not 100% airtight. They can steadily meter the flow of materials without losing a significant amount of air, which makes them integral to bulk material processing. They’re so integral because they provide a controlled feed rate all the while minimizing air leakage between the components of the pneumatic system. Rotary airlock feeders can also be used as volumetric feeders in order to meter materials from bins and silos onto a conveying system. They can also act as a gravity discharger for cyclone dust collectors and filters. 

At Carolina Conveying, we offer a wide variety of airlocks for all types of applications, ranging from industrial to sanity to high process rate. 

Differentiating Parts and Terms

Other words you’ll also hear tossed around are rotary valves, rotary airlock, and rotary feeders - and it can get confusing as to when each term is appropriate and whether or not they all mean the same thing. 

With rotary valve applications, terminology is important. Each valve has a different job, meaning these terms are not interchangeable. 

Rotary Valve

A rotary valve on its own doesn’t have a home or a purpose. Its application must be determined by accessories that determine whether it turns into an airlock, a feeder, or both. 


The valve that separates the pressure differential sealing of airflow from a hopper, bin, or conveying line is called an airlock. These are typically found in the beginning of a pressure system or the end of a vacuum system. 


Other pieces of machinery that could also be considered airlocks include rotary valves, knife gates, butterfly valves, or double dump valves. 



The main purpose of a feeder is to measure material as it’s going in or out of something, but it is not separating a pressure differential. There are a number of types of feeders, including volumetric feeders, vibratory feeders, screw conveyors, or rotary feeders. 

Rotary Airlock Feeder

As we stated previously, the rotary airlock feeder separates a pressure differential while still allowing material to pass through. To get a good idea of how a rotary airlock feeder works, you could compare it to a revolving door. Materials (or people, in the door’s case) can pass through, but the device still maintains the pressure differential between the inside and outside of the building. 

Our Rotary Airlock Feeders

Carolina Conveying is a leader in the manufacture and design of exemplary rotary airlock feeders. Our custom-built valves are dependable, safe, and minimize pressure loss. 


Here are the products we offer: 

Drop-Thru Rotary Airlock Valves

A rotor with tight tolerances and minimal leakage, the Drop-Thru Rotary Airlock Valve is our most popular unit. It has heavy-duty castings for the body and end covers, with thick vanes and large shaft rotors that are guaranteed to hold tight tolerances. It also comes in a wide array of sizes. 

Side Entry Rotary Airlock Valves

The Side Entry Rotary Airlock Valve eradicates the likelihood of your application shearing or jamming. Since it has a V-shaped throat feature, it’s designed to push products out of the way and prevent the rotor vane from meeting the side of the rotary airlock and jamming the valve. 

Blow-Thru Airlock Valves

Designed for pneumatic conveying applications, the Blow-Thru valve deals with both positive pressure and vacuum systems. The valve has ports on the same sides as the end covers, and those connect to the convey line, which allows convey line air to blow out through the rotor pockets - and this saves energy and power consumption! 

Easy Clean Rotary Airlock

The Easy Clean Rotary Airlock contains a quick-release motor that can be removed without disconnecting the drive package. This works well in food applications when the valve must be cleaned on a regular basis. 

Standard Duty Rotary Airlock Valves

A Heavy Duty Airlock costs a lot of money, but the Standard Duty Rotary Airlock Valve is an affordable alternative. When a high robust valve isn’t required, like handling it on the bottom of a duster collector, or handling free, dry, flowing non-abrasive materials, it’s a great component to use. 

Special Size Rotary Airlock Valves

Everyone’s airlock needs are unique, which means our standard options might not be what you’re looking for. We offer Special Size Rotary Airlock Valves that range from rectangular units to larger bore bodies. 

NFPA Design Rotary Airlock 

If you have a deflagration isolation system, you need a valve that meets or exceeds the NFPA 68 and 69 requirements. Our NFPA Design Rotary Airlock is the most heavy duty valve there is, available in sizes 6-24 inches in cast iron and stainless steel. 

Carolina Conveying

At Carolina Conveying, we want your machinery to perform exactly as it should. Come talk to us today about which Rotary Airlock Feeders might work for you.