Rotary Airlock Valves

Rotary Valves minimize air pressure loss and increase efficiency.
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Rotary Airlocks

Rotary Airlock Valve Feeders manufactured by Prater are designed to provide improved performance to bulk material processing and production operations. In dry material metering applications, our valves ensure accurate material loading and unloading while also functioning as highly efficient rotary airlocks; minimizing pressure loss throughout the system.

Our customers rely on Prater Rotary Valve Feeders to perform various functions such as:

  • Feed process materials into pneumatic conveying applications
  • Regulate the flow of material from one chamber to another
  • Metering of process materials in loading and unloading applications
  • Minimize air loss while transferring material between vessels with different pressures

Prater’s Rotary Airlock Valves can be configured and customized for most application requirements, especially for materials that may be highly abrasive. We understand the need for feeding more material at lower speeds, which is why our rotary airlock feeders are manufactured with larger pockets. In turn, this design minimizes air leakage, provides the benefit of longer life, and ensures a higher return on investment.

Wherever dry free-flowing powders, granules, crystals, or pellets are used, our rotary valves perform well in a wide range of industry applications. Common materials include cement, ore, sugar, pigments, wood chips, minerals, grains, plastics, coal, soy white flakes, fly ash, flour, gypsum, lime, coffee, carbon black, and pharmaceuticals.

Our Rotary Valves incorporate an advanced set of features that provide numerous benefits for our clients:

  • CFR (Cubic Feet per Revolution):  Industry leading CFR allowing up to 50% more volume per revolution.  This enables the rotor to run at lower speeds than other manufacturers, increasing efficiency and equipment life.  Alternatively, it may allow for a smaller Prater airlock to be specified than the competitors.
  • Castings: Precision machined, heavy-duty cast iron or stainless steel construction providing long life and durability with minimal air loss at operating temperature ranges. Designed for up to 15 psi differential pressure. Perfect for pneumatic applications.
  • Universal Flanges: Oversized design able to accommodate multiple bolt patterns for a wide range of installations.
  • Rotors: Precision machined eight-blade, heavy-duty fabricated design ensures minimal deflection and improved seal as compared to 6 blade designs.
  • Design: Compact size and head height allows for easy installation or replacement of most competitors airlocks. Standard transitions required to replace competitor airlocks provided at no cost.
  • Motors: Inverter-duty designed with integrated gearboxes and heavy-duty chain drives (direct drive available).
  • Bearings: Easily replaceable, outboard-mounted, maintenance–free lubricated bearings.
  • Packing Glands: Self-adjusting design ensures consistent load on packing to reduce leakage and help extend shaft seal life. Designed for simple maintenance.
  • Operating Temperature: Standard models operable up to 500 ℉. Custom models up to 1000℉.
  • Standards: Compliant with NFPA-69 standards. Third-party tested.


  • Heavy-duty and precision machined castings for superior lifespan and minimal air leakage.
  • Our universal flange allows for the flange hole mounting pattern to match the customer needs.
  • Compact geometry ensures maximum displacement relative to footprint-size.
  • CFR (Cubic Feet per Revolution):  Large CFR’s potentially allowing for a smaller airlock than the competitors or reduced RPM  which typically lengthens the lifecycle.
  • Large feed throat design for maximum fill of rotor pockets.


  • Precision fabrication for industry-leading rotor-to-housing design clearance minimizes air leakage.
  • Eight-blade designed for smooth operation and maximum seal.
  • Custom-designed application solutions for rotor specifications.


  • Consistent 5.1 torque ensured by inverter-duty motors (5:1 turndown for standard inverter duty motor).
  • Prater standard drives are a premium design that offers more HP for what others consider a heavy duty upgrade.
  • Quadralip seals provide maximum protection against contaminants.
  • Uni-case housing ensures maximum oil, seal, and bearing lifespans while running with less noise.


  • Outboard-mounted for easy access and maximum strength.
  • Easy maintenance ensured with quick-change packings.
  • Designed with more space between the bearing and seal plate that allows for packing change with the valve fully assembled.
  • Self-adjusting packing glands provide constant pressure during operation.
  • Bearings sealed for life to provide no-maintenance-required airlock lifecycle.


  • Our team members are able to correctly match the features with the application and thus stand behind with the configuration. We are the experts for the application and the equipment.
  • We strive for “same day” quoting for standard airlocks and industry leading delivery times.
  • Provide STEP files of the product on our website to reduce engineering efforts.
  • Prater offers a Price Match guarantee, e.g. we will match a competitors price for the same airlock with the same features.
  • We will offer standard transitions required to replace a competitors airlock with a Prater airlock at no cost.

We manufacture several application-specific models for the varied industries we serve:

  • Heavy Duty Models: Prater heavy-duty PAV series is the workhorse of the industry.  Numerous options for rotor designs, seals, and accessories. Designed for dry, free-flowing solid particles in gravity-driven or pneumatic systems.
  • Quick Cleaning Models: Prater QTA and BAV series are designed with direct drive and 2-piece rotors for easy, tool-free maintenance. Pre-gapped rotors eliminate the need for post-installation adjustment. The BAV series is equipped with a linear rail system for easy rotor setup and removals.
  • Abrasion Resistant Models: This is the most durable model available anywhere. Hardened rotor tips, premium seals and specialty (tungsten, chrome, or ceramic) wear coatings are standard. Manufactured especially for use with abrasive materials.
  • Blow-Through Models: Prater blow-through series is designed and manufactured specifically for applications that require discharging into a pneumatic conveying line. These Airlocks are ideal for free-flowing materials that require some assistance in clearing the rotor vane pockets. The design of the Prater Blow-Thru Airlock makes installation possible in low headroom applications and retrofits of existing rotary valves.

After years of engineering and manufacturing rotary airlocks, we consider ourselves proven experts on the various rotary airlock and valve designs available to our customers. We understand that temperature, pressure, size and construction plays a very significant role in processing various materials which is why all of our rotary airlock valves are carefully machined for those unique specifications. Each of our rotary airlocks can be individually customized to your exact processing specifications to ensure optimal, reliable and worry-free operation that meets your precise needs.

Our airlocks have an innovative larger vane pocket design that allows up to 50% more volume which enables the rotor to run at lower speeds than other manufacturers’ rotary airlock and valve feeders. Pair this with our exclusive self-adjusting packing glands and you have a rotary airlock valve that provides minimum air leakage, a longer life, less maintenance and a higher return on your investment.

Other standard features such as our precision casting, CNC machining, compact design, and universal mounting flanges allow for a versatile material handling rotary airlock valve product that can fit virtually every existing bolt hole pattern and replace any existing rotary valve.

If you have a need for a rotary feeder, please consider the added “airlock” benefit of a Prater Rotary Airlock Valve. We are confident that we can help improve your bulk material handling and conveying efficiency.

Contact Prater today and discuss your airlock application with one of our rotary airlock account managers. They can quickly help you select the best rotary airlock for your application and recommend specific options to meet your processing requirements.

Let us know if we can serve you. We do custom builds, so if there is anything special that you require in rotary airlock feeders, our experienced staff will work hand-in-glove to develop and manufacture it for you. Similarly, if you already own a Prater airlock device and it needs servicing, we welcome your call.


Try our Airlock Size Recommendation Tool: answer a few simple questions and we’ll provide a recommendation on what size airlock to use.