Understanding the Rotary Valves in Your Pneumatic Conveyor System

If you run a business that has bulk handling needs to move items from one area to another for processing, then it is wise to invest in a device like a pneumatic conveyor system. These systems use air in a vacuum tube system to drive or move the conveyor, and they have many benefits over mechanical conveyors. Pneumatic conveyors have a variety of different parts and pieces that need to remain in good condition if you want your material processes to go smoothly. One of these parts is called a rotary valve. Keep reading to learn about this part, what it does, and how it can be cared for.

What Is a Rotary Valve?

Rotary valves are cylindrical valves that contain a central or middle part that spins. This part of the valve is fitted with openings. These openings may be holes in the cylinder or they may be spaces in between a spindle or blade device. The cylinder part of the rotary valve controls the flow of air through the pneumatic system. This helps the conveyor to maintain a consistent speed with constant air flow.

Rotary valves can range greatly in size from small to extremely large. The smallest ones are seen on bras instruments like tubas and trumpets while the larger ones are constructed for use with milling, baking, and other good processing machinery. The types of valves used for pneumatic conveyors are medium sized varieties.

Rotary valves are typically made with steel casings and steel spindles as well. The devices are attached to the closed air pneumatic system that controls your conveyor. When the system called for more air, like when you increase the speed, the valve will turn so the openings in the cylinder are more inline with the air tube inlet and outlet. More air will then move through the system and increase pressure.

How Do You Care for Rotary Valves?

Rotary valves are enclosed valves that are rarely thought about. Some business owners may not even know where the main valve is located on the pneumatic system. If you are unsure, then look for the air pump and motor. The motor will be attached to a hose and a filter. This hose will feed into the rotary valve and a hose will leave the valve and run to the conveyor system. You also may have a control panel that sits near the valve.

Once you find the valve, use your hands to feel around the casing while the pneumatic system is running. All rotary valves will cause some air leakage since the valve itself will cause some resistance within the part. However, you want to make sure that leakage is not severe. If you feel light air pressure coming from the valve when the system is on, then this is normal. If air pressure is strong or fast, then the valve casing may need to be tightened. Look for the bolts on the outside door or end cover of the valve and tighten them.

If tightening the attachment does not help to contain air within the system, then the gasket inside the cover may need to be replaced. 

You also need to look at the bearings that fit into the end cover. Most bearings are sealed varieties that are filled with grease and covered with a neoprene coating. While sealed bearings are meant to last a long time without the need for replacement, they will sometimes need to be replaced. Bearings that have corroded or that have started to leak oil or make grinding noises are no longer in good shape. To inspect the bearings, remove the end cover and look for the bearings on the inside. 

While inspecting the bearings, you want to inspect the shaft seal on either end of the rotary cylinder. There are a wide variety of seals that may be used. Make sure the seal is intact without cracks or damage. 

For more information or assistance, contact companies like HAF Equipment Inc.