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Fire safety at the core

  • 8-Vane completely steel rotor*

  • Ignition point removed entirely with outboard bearings

  • Close Clearance configuration to quench any possible ignitions.

Rotary Airlock has engineered and developed NFPA Compliant Valves that exceed safety standards across all makes & models. With thick carbon steel housings that are hand-welded and individually inspected, you can rest assured your valves are built to withstand the pressure of a fire.

You won't find any rubber or plastic-tipped vanes either. Rotary Airlock's NFPA Valves contain at least 8 completely steel vanes instead of the non-compliant 6 or rubber-tipped vanes of some valves (primarily dust collectors). These completely steel vanes carry clearances no more than .0079in from the housing too. This NFPA compliant clearance suffocates a fire, quenching its oxygen supply and helping contain the flames, ultimately aiding extinguish it.

That's just the base of each model. Can we introduce you to a maintenance and compliance dream outboard seal & bearing system too?

Rotary Airlock's proprietary Rapid Access endcap configuration on NFPA compliant valves carries an outboard CLF Bearing System and Rotary Airlock's proprietary MAP Seal System.


With this NFPA & Maintenance focused configuration, you can monitor and completely change seals & bearings In-Line and in under 15 minutes so get the best of safety and convenience today.


Completely Steel Rotor

Ignition Point Removed

Change Seals & Bearings In-Line

With at least 8-Vanes, these rotors are completely steel, so standing up to the heat is a walk in the park.


Then clearances under .079in these rotors help suffocate fires too, keeping them from spreading and aiding extinguish flames sooner.


With Rotary Airlock's CLF Bearing System, the Rapid Access endcap configuration has removed the ignition point from the equation entirely.

You can rest easy knowing your valves won't become a fire hazard. 

In less than 15 minutes, you can change our proprietary MAP Seal and CLF Bearing Systems In-Line.

No need to pull an airlock means less downtime, less labor, and more product & profit for your bottom line.



Those upgrades are just the base for every NFPA compliant valve Rotary Airlock manufactures. We have gone even further to offer Direct Drives for ANY make & model as well.


This Plug-N-Play set-up is the industry safety standard that minimizes access to moving parts and alleviates additional parts &  inventory requirements. It also requires less maintenance time & labor, thus saving your budget and ultimately increasing profits all while eliminating hazard points for you and your team.

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Starting with Rotary Airlocks premium construction standards, (American Sourced, carbon steel, hand-welded, full steel rotors & housing, with close clearance configurations, and maintenance geared outboard systems), makes Rotary Airlocks NFPA compliant valves what the rest of the industry strive to be.

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With so many valves (especially dust collectors) fabricated from foreign gauged rolled steel and containing rubber-tipped vanes (wiper blades), the safety of your plant and people needs to start right at the construction standards of your equipment. Here is a look at Rotary Airlocks NFPA compliant dust collector construction materials and thickness.

Outboard CLF Bearing System

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3/4" Carbon Steel Housing

5/8" Carbon Steel Endcaps

Completely Steel Vanes

Close Clearances (.0079 or less)

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                                 With the dust collection system doing, well, precisely what it's supposed to,

                                 collecting dust, it becomes the perfect fuel for a plant fire or explosion. It's a system

                                 of highly flammable, well-ventilated material that has an express lane across a plant.

                                 Dust Collector valves within that system could play a significant role in containing a

                                 fire before it travels further down the line.


All Dust Collectors are non-compliant because they have rubber-tipped vanes that

can't withstand heat from a fire or contain an explosion.  Let's not forget the housing.

All Dust Collector housings have thin sheet steel that is bent into shape. These

valves can't stand up against the pressure from an explosion, allowing a fire to

expand and grow.


All Dust Collectors have non-compliant inboard bearings. When a seal fails, it allows

product to get to the bearing ultimately making the bearing fail too. Bearing failure

can lead to metal-to-metal contact,  leading to sparks. This turns a dust collector into

a flint and tinderbox, sparking a fire with no obstacles to contain or extinguish it.



When a rotary valve needs repair or maintenance, resulting issues can create a fire risk. Leaking material, for instance, is a source of combustible dust. Strange noises can indicate product buildup or increased rotor clearance — a vital sign of a non-compliant valve.


Worn-out or damaged parts can increase the risk of fires, deflagrations, or explosions in a  plant. Keep a close eye on the following valve parts and equipment:​

Rotor Vanes: Rotors should have a minimum of eight vanes. To keep flames contained within the rotor pockets, at least two vanes must stay in contact with the housing at all times. That means a six-vane rotor won’t do. The vanes must be at least 3 mm thick.


Rotor Tips: Rubber or plastic rotor vanes can’t withstand the heat of a deflagration, so make sure your rotor is equipped with steel vanes. (ie. Rubber Tipped Dust Collectors ARE NOT NFPA Compliant)


Shaft Seals: Worn-down shaft seals often cause leaks, which increase the risk of fire as a source of combustible dust. Replace shaft seals and packing regularly to prevent the issue.


Dust Collector Filters: To prevent clogs and minimize issues with your dust collectors, including the buildup of combustible dust, keep extra filter bags or cartridges handy.


Long Radius Elbows: Conveying long radius elbows degrade faster than most other parts, and wear can lead to a drop of pressure and leaking material. It’s useful to keep extra elbows in stock to fix the problem.


Rotor-To-Housing Tolerance: Proper clearances are imperative in an NFPA-compliant valve. You must regularly check your valve’s rotor-to-housing clearances, or tolerances, to make sure they stay at 0.0079in. or below. If they get any larger than that, it’s time to replace the valve.



Aside from regular repair and maintenance, you can take several precautions to ensure your rotary valves and conveying system comply with NFPA regulations.

On the valve side, the right outboard bearings will reduce material buildup (a fuel source) and prevent friction (a source of ignition). Rotary Airlocks CLF Bearing System removes the possibility of both. Proper shaft seal assemblies should reduce heat and static electricity.​

It’s worth stocking up on the valve parts mentioned above to ensure you can quickly replace them when the time comes.

If you need an entirely new rotary valve, you should be looking at options that are NFPA compliant as a standard, and with construction standards that are NFPA compliant. Take a look at housing thickness and steel choices for example. 1/2" thick, American Sourced, Carbon Steel like what Rotary Airlock has a production standard for manufacturing all of our valves from, IS NFPA compliant. Gauged, Foreign Sourced, Rolled Steel that is prevalent in the industry is NOT.


Always transport heat-sensitive bulk materials under appropriate temperature, humidity, and conveying gas conditions. Besides that, proper ventilation and regular plant housekeeping are critical. Make sure to stay on top of your preventative maintenance schedule and keep historical logs of everything you do.


Rotary valves help or hinder your fire safety efforts, depending on how they’re made and maintained. It’s essential to understand how fires and deflagrations start in a manufacturing facility.​ Manufacturing and processing properties tend to be more prone to structural fires, and conveying systems are rife with combustible materials. Fires start when fuel, an oxidizer, and an ignition source come into contact with each other. Deflagrations are more complicated — and more dangerous.​ When a heat source moves over and ignites cold materials, it creates a form of combustion called deflagration. This is a fast-moving fire that can spread across manufacturing lines and consume more material as it progresses, creating a chain reaction that is difficult to contain.​

Key Components To Be Aware Of

5 Conditions that start a Deflagration:

     1. Fuel, which comes in the form of combustible dust

     2. An oxidizer, which often means too much oxygen in your system
     3. An ignition source, such as friction or overheated material
     4. Dust particles concentrated in one area
     5. Dust particles confined to a small space

       The latter two may take the form of dust clouds in the air or on your machinery.

Rotary valves play a big part in controlling these conditions. They manage fuel and ignition sources and limit the amount of oxygen feeding the flames. In other words, when a fire breaks out, valves act as isolation devices to stop the spread of fire along your conveying line. That said, an NFPA compliant rotary valve has specific design and construction elements. It also needs regular maintenance and repair to keep it operating safely. To stay compliant, make sure your valve is outfitted with the right parts and watch for signs that your system needs attention.

If you have any questions or concerns with your valves and NFPA compliance

contact Rotary Airlock at (815) 626-0388 or

The NFPA broadcasts their guidelines in book or .pdf format for purchase. These are really wordy with a ton of people's names that are useless to you and full of legal jargon. Worse yet you have to pay for it.


We have provided a FREE guideline of ALL of the DIRECT measures to make sure you're airlocks are operating within the NFPAs Code.

Download guideline here

How do I know if my valves are NFPA compliant?


If you find that you are not in compliance not to worry.


We have the knowledge & expertise to reconstruct your existing airlocks to comply with NFPA-69 guidelines or fabricate a completely new custom airlock for your system that fits within those guidelines.

What if I'm not in compliance?


Absolutely Not! Rotary Airlock can, and has, engineered and reconstructed ALL makes & models of airlocks to be NFPA compliant across all industries.


So you'll get YOUR airlock, the way YOU deserve without gouging your budget.

Do I really have to buy whole new valves?


Last year in the US alone large-loss fires (those with over $10 Million in losses) resulted in 52 deaths, 233 injuries, and an estimated $12.5 billion in direct property losses.


Don't let the loss of those dollar signs and, more importantly, the loss of those human lives land at your feet.

Why do I need to be NFPA compliant?


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