Getting to Know the Rotary Air Lock Valve

No matter which conveying technology you use to handle your materials, you want it to run as smoothly and efficiently as possible. Pneumatic conveyors rely on rotary airlock valves to make this happen. Without these parts, you’ll encounter series of issues that will cause damage to your bulk, as well as your finances.

These valves, also known as rotary airlocks, rotary feeders, or some other variation, enable the materials to pass between chambers without getting airborne. Air is full of contaminants that can severely undermine the quality of your materials. Also, in the event of a dust explosion, valves are there to provide flame protection. Check this website to learn more.


How Do They Work?

You don’t have to be a professional engineer to understand the concept of a rotary airlock. There are rotating metal blades (or vanes.) When turning, they create pockets where the material enters, rotates, and finally exits through the outlet port.

During this process, the air is locked between the ports. This is how airlock valves got their name. It enables the bulk to pass with the help of constant air pressure and restricted airflow. The condition is that you must maintain continuous pressure for the valve to function as it should.

Diversity and Application

Airlock valves are highly versatile. If you’re familiar with pneumatic conveyors, you’ll know that you can use them in various industries with all kinds of materials. Don’t let the simple design fool you: these things are real Swiss Army knives.

You can use them in any situation involving the transfer of granules and powders, such as chemicals, pharmaceutical products, food materials, wood chips, etc. Recycling also makes excellent use of rotary valves. Depending on the temperature and materials, it’s possible to customize the size and shape of the pockets mentioned earlier, or even change the inner lining.

Choosing The Right Valve

There’s a good reason for the wide range of rotary valves available on the market. While each of them essentially serves the same purpose, there are several factors to consider when deciding which one’s right for you.

First of all, it depends on what bulk material you’re processing. For instance, if you’re moving abrasive materials such as cement, asphalt, aggregate, and others, you’ll need valves with chrome coating and steel rotor tips. They’re specially designed to resist abrasion and will last longer without wearing off. Go to for more information.

Then, you need to have the operating temperature in mind. When exposed to heat in the neighborhood of 1400°F, your valves will need heat-resistant sealings and bearings, special couplings, and so on. Other factors are the type of application, what level of abrasion resistance you need, moisture level, material density, etc.

When looking at the specifications, you’ll find that some valves have open-end rotors, while others have the closed-end variation. The difference is that the former is used for abrasive materials, while the latter is more suitable for pellets. Obviously, you should do some research before buying your valve, otherwise, you’ll end up wasting time and money.

Wear and Tear

Just like any other mechanical components, these valves are subject to failure after prolonged use. Typically it’s because of a worn rotor or housing, or sometimes both. If you’re transferring abrasive materials, you’ll probably need to replace the parts sooner than you expect.

This happens when materials that move in opposite directions get trapped between surfaces. Or, the abrasion can be caused by turbulent air at the outlet port. This is why you have to keep an eye on material processing: preventing unnecessary damage to the components will extend your valves’ lifespan and keep your bulk protected.

Some Extra Tips

When buying airlock valves, you should look for a company that provides many options and designs. Quality manufacturers are aware of the many industrial applications, so they’ll try to address your individual needs and advise you along the way.

You’ll recognize a quality air lock valve by the cast iron construction, precision-machined housing, outboard bearing design, and several other technical specs. For example, the inlet needs to be “open throat” for optical material flow to the rotor pockets.

Conveying materials could involve some electrical hazards if you don’t watch out. A good idea is to ground your system with copper wire, especially when transferring plastic pellets or other materials that involve static electricity. Grounding also protects your workers from getting an electric shock. Also, it prevents combustible dust from catching fire and creating an explosion on your premises.

Handling equipment is a responsibility. Before putting your valves into action, you should always check the operator’s manual or consult your manufacturer if something’s unclear. Also, it’s vital to follow the LOTO (lock out, tag out) safety procedure at all times. This method is required by law in some countries, and it’s the only way to ensure the absolute safety of your employees.

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