Material handling valves come in all shapes, sizes, varieties, and with hundreds of available options. From rotary valves and knife gate valves to double dump valves and trickle valves the choices are nearly endless. With such a vast selection available, choosing the right material handling valve for a given application can be a difficult task and choosing the wrong valve can be costly.

While there may be more than one possible solution to a material handling need, there is often a best solution to be found if the proper considerations are given. Here are the top five questions any plant manager or plant engineer should ask when choosing a material handling valve.

What is the nature of the material being handled?

The most important consideration for any material handling application is, of course, the material itself. The characteristics of the material being handled will determine which type of material handling valve should be selected. Extremely fine materials typically require a valve with tight tolerances and seals to prevent dust from escaping into the atmosphere. Coarse or chunky materials often require larger clearances to help prevent plugging or jamming of the valve mechanism.

Will the Material Handling Valve Meet Your Operational Parameters?

Not all valves are created equally and the environments they are expected to operate in vary as well. In many cases material handling valves are put to use on systems with some degree of atmospheric pressure differential. Most material handling valves are intended to be airlocks as well; allowing solid material to pass through the system without allowing major pressure losses. Be sure to select a material handling valve that has a pressure rating within the range it will be expected to operate.

How should the valve be powered?

All too often, plant maintenance personnel accept the “standard” valve control type listed by the manufacturer rather than choosing the best actuation method for the job. Pneumatic cylinders are the most widely used actuators for knife gate valves and many other process valves due to their continuous-duty rating and readily available shop air supplies. While pneumatic controls may appear to be an easy and convenient method to operate a knife gate valve, a manually operated unit may be more suitable and cost-effective for maintenance valves which are operated very infrequently.

How easy is it to maintain?

Regular maintenance is a must for any material handling valve. As valve parts wear or material build-up occurs, the need for replacement, repair, and cleaning of the valve is inevitable. When choosing a material handling valve, close attention should be paid to how easily the valve will be to maintain. Quick-release access panels, change-in-place parts, and easily accessed wear parts all make the job of performing regular service on a valve much easier.

How much will it cost?

While the initial investment for a material handling valve is important, it is only part of the equation. Frequent repairs or labor-intensive repairs to a valve can easily eat into any initial savings in cost. The cost of process downtime due to maintenance needs can become magnified if the valve cannot be repaired in place or replacement parts are not readily available.

Doing the proper due diligence also goes a long way in selecting the best material handling valve for a given application. Realistically, the success of a material handling valve comes down to the careful consideration of application parameters and how much time and effort is given to make sure the appropriate valve is selected.

For more literature on material handling and airlock valves for peak system performance, visit the library tab on our website at www.dustcollectorhq.com.

To improve efficiency and safety, there is no substitute for an on-site inspection by an experienced expert. Click here to speak with our applications engineer about selecting the right material handling valve for your application. 

Rotary valves will occasionally jam. This can happen when material gets between the rotor and the housing or when oversized material cannot fit into the rotary valve pockets.   Depending on the type of jamming that is happening you handle the situation differently.

Space Between Rotor and Housing

Rotary valves have a space between the rotor and the housing. This space allows the rotors to rotate freely but it can also allow air to leak across the valve. When materials falls on the rotor edge it can buildup and jam the rotary valve. So for existing rotary valves, you might have to replace or modify the existing rotor. Beveling or chamfering the rotor edges help the material to fall off the edge and into the valve pockets.

When Jams Caused by …

For jams caused by oversized material, a valve with larger pockets is required. This could mean a larger rotary valve or replacing the rotor with a rotor containing one less pocket. Please note if the rotary valve is on an explosive application, NFPA requires a minimum of six vanes on the rotor. If these options aren’t possible, looking into a double dump valve might provide larger clearance for oversized material to pass through.

For case studies, more blog posts, and application content, visit our website’s library of resources at www.dustcollectorhq.com.

To improve efficiency and safety, there is no substitute for an on-site inspection by an experienced expert. Click here to connect with our applications engineer about your application.

Aerodyne now offers its pneumatic knife gate in a washdown design for flow control.  All parts are stainless steel or aluminum to prevent corrosion after washdown cleaning.  The washdown design has a cast aluminum body and stainless steel knife, support bracket, cover, pneumatic cylinder shaft and hardware, preventing corrosion after washdown cleaning. All these factors mean the StopTight Knife Gate can better handle streams of tough materials and solve more complex problems.

The design has proven effective and economical for companies already. For example, a US company that specializes in producing dough in the food industry needed a valve that would allow them to have control of the flow of ingredients into the tank. The valve needed to be made up of stainless steel and aluminum due to the difficult conditions of the tank. Looking for suggestions, the company contacted Aerodyne.

Aerodyne suggested the facility use the StopTight Knife Gate Valve in a washdown design as a flow control valve. The StopTight Knife Gate Valve can be used either in the line of flow or at the point of discharge. Using a linear motion, a blade advances until the passage is closed or it withdraws until the passage is open. In the closed position, the knife gate valve is designed to seal tightly. Aerodyne’s washdown pneumatic knife gate design effectively regulated the introduction of contents into the mixing tanks while adhering to food-grade specifications, helping the company to create dough and earn more dough.

3) Choose the Right Material Handling Valve for Your Material

What’s up with your dust? Probably the most important consideration for any material handling valve application is the material itself. The characteristics of the material being handled will determine which type of valve should be selected. Extremely fine material typically requires a valve with tight tolerances and seals to prevent dust from escaping into the atmosphere. Coarse or chunky materials often require a valve with larger clearances to prevent plugging or jamming of the valve mechanism. A common problem some rotary valves experience is large chunks of material becoming jammed between the rotor vanes and valve housing. While some design innovations help prevent this issue, the best solution may simply be selecting a different material handling valve that is better suited to the material.

Double dump valves, also known as double flap gate valves, are designed to allow large, chunky, and abrasive materials to pass through with minimal chance of blockage. Pairing the proper material handling valve with the material being handled is crucial for a successful installation and improved dust collection efficiency.

2) Will The Valve Meet Your Operational Parameters?

Not all material handling valves are created equally, and the environments they are expected to operate in vary as well. In many cases, material handling valves are installed on systems with some degree of atmospheric pressure differential. Most are intended to function as an air lock valve for dust collector applications, allowing solid material to pass through the system without significant pressure losses. Be sure to select a material handling valve with a pressure rating that matches the conditions in which it will operate.

Temperature is another operational condition that should be taken into account. Any gaskets or synthetic seals should be rated to handle the expected process temperatures. High-temperature bearings or bearing stand-offs should be utilized in order to maintain functionality in extreme conditions. Abrasive or corrosive materials may require special material construction. So again, it is imperative that you really know and understand your dust!

In addition to atmospheric conditions, it is also important to consider the type of work demanded of the material handling valve. A rotary valve intended for use as a material feeder may have far different requirements than a rotary valve intended for use as a dust collector rotary airlock. Likewise, an industrial knife gate valve intended to meter material flow will have a very different service life than one used strictly as a maintenance valve to shut off material flow during periodic system maintenance. Always consider the duty cycle and performance expectations placed on the valve.

3) Powering Your Material Handling Valve

All too often, plant maintenance personnel accept the “standard” valve control type listed by the manufacturer rather than choosing the best actuation method for the job. Pneumatic cylinders are the most widely used actuators for knife gate valves and many other process valves due to their continuous-duty rating and readily available shop air supplies. While pneumatic controls may appear to be an easy and convenient method to operate a knife gate valve, a manually operated unit may be more suitable and cost-effective for maintenance valves which are operated very infrequently. Many double dump valves use pneumatic cylinders to provide a precisely timed open-close sequence.

In some cases however, a specific timing sequence is not as crucial as consistent and reliable operation. A mechanically operated double dump valve using an electric motor-driven cam offers lower cost and fewer components to fail or replace. A trend in powering rotary valves is the use of electric gear motors which combine an electric motor and gear reduction box into one compact unit. While this method of operation has its advantages, it lacks the flexibility of a traditional chain drive assembly.

One type of material handling valve gaining popularity in dust collection systems is the non-powered automatic trickle valve. These valves utilize the negative pressure of a cyclone or baghouse to hold a rubber sleeve closed and create an airlock seal. As material builds up on top of the valve, it automatically opens to discharge collected dust. Trickle valves work best with dense, free-flowing materials and are typically a fraction of the cost of many other dust discharge valves.

Click here to watch an animated demo of a trickle valve system

4) Material Handling Valve Maintenance

Regular maintenance is a must for any material handling valve. As valve parts wear or material build-up occurs, the need for replacement, repair, and cleaning of the valve is inevitable. When choosing a material handling valve, one needs to pay close attention to how easy (or not easy) the valve is to maintain. Quick-release access panels, change-in-place parts, and easily accessed wear parts all make the job of performing regular service on a valve much easier.

Another aspect that will affect the maintenance of a valve is the valve’s overall reliability. Even a valve with easily accessed or easily replaced parts can still become a maintenance nightmare if those parts frequently break or wear out. Choosing a valve for reliability and ease of maintenance will help to save time and money over the life of the valve.

5) How Much Will it Cost?

While the initial investment for a material handling valve is important, it is only part of the equation. Frequent repairs or labor-intensive repairs to a valve can easily eat into any initial savings in cost. The cost of process downtime due to maintenance needs can become magnified if the valve cannot be repaired in place or replacement parts are not readily available. For dust collection systems it is often recommend to install a knife gate valve above the primary material discharge valve to be used as a service valve. The knife gate can be used to temporarily seal the system while maintenance is performed on the primary valve. Although the addition of a knife gate valve to the system adds to the overall cost, the benefit of avoiding a system shutdown during maintenance can far outweigh this cost.

Doing the proper due-diligence also goes a long way in selecting the best material handling valve for a given application. Just because a rotary airlock is the most familiar type of valve does not mean it is the right type of valve for the job. There may be a less expensive type of valve that can easily handle the same task or a more expensive valve that is more appropriate for the application. Realistically, the success of a material handling valve comes down to the careful consideration of application parameters and how much time and effort is given to make sure the appropriate valve is selected.

Dan, understanding that the company had used a manual StopTight Knife Gate Valve in the past and was happy with the results, looked at the needs of the company and suggested that they use a 12” pneumatic Knife Gate valve with a position switch. The Knife Gate is an ideal solution to the company’s problems due to the fact that this product provides an effective way to control the flow of a variety of materials in differing operating conditions, either at the line of flow or the point of discharge. Furthermore, the Knife Gate sits tightly on a material handling system, which prevents loss of positive or negative pressure in the system, making it an ideal way to control discharge.

Furthermore, the Knife Gate Valve seals tightly on material handling systems, preventing the loss of positive or negative pressure within the dust collection system. This makes it an ideal solution for controlling material discharge while maintaining efficient dust control.

Aerodyne offers a wide selection of Knife Gate Valves designed to handle a variety of materials and operating conditions. From manual Knife Gate Valves to pneumatic Knife Gate Valves for dust control applications, Aerodyne has a solution for nearly every application. A variety of sizes are available, including industrial Knife Gate Valves for open hopper discharge or in-line use, with some models capable of closing through a static column of material.

A US company that specializes in producing dough in the food industry recently contact Aerodyne for a custom order. The company mixes all of its ingredients in a massive tank. They were looking for a valve that would allow them to have control of the flow of ingredients into the tank, but the valve needed to made up of food grade materials. Looking for suggestions, the company contacted Aerodyne.

Aerodyne suggested the facility use the StopTight Knife Gate Valve. This material handling valve is used as a flow control valve. It can be used either in the line of flow or at the point of discharge. Using a linear motion, a blade advances until the passage is closed or it withdraws until the passage is open. In the closed position, the knife gate valve is designed to seal tightly and prevent the loss of positive or negative pressure of the system. Aerodyne has a large selection of knife gate valves which can be used to handle a variety of materials and operating conditions.

There are very strict rules and regulations in the food industry that companies must follow. All of the equipment used in processing or handling the dough must be made of good grade materials. Aerodyne was able to fabricate a knife gate valve made of aluminum, stainless steel, and nylon to effectively control the introduction of contents into the mixing tanks as well as stay with in the regulations.

A bakery in IL was in need of material handling valves that would allow control of its baking materials. Specifically, the company needed something that would permit the addition of solids in to the baking process with ease and precision. After seeing a press release for Aerodyne’s StopTight Knife Gate Valve, the company reached out to Aerodyne for more information.

A knife gate valve is used as a flow control valve in a bulk-material handling system, either in the line of flow or at the point of discharge. Using a linear motion, a blade advances until the passage is closed, or it withdraws until the passage is open. In the closed position, the knife gate valve is designed to seat tightly and prevent the loss of positive or negative pressure of the system. Aerodyne has a large selection of Knife Gate Valves which can be used to handle a variety of materials and operating conditions. From manual valves to pneumatic valves for dust control, Aerodyne has a knife gate for almost any application.

Aerodyne suggested the company use three 12” pneumatic knife gate valves that have aluminum housing and a stainless steel blade for its operation.

To find out more about how the knife gate can help introduce control to your material handling process, click the photo below.

A knife gate valve is used to control flow in a bulk-material handling system, either in the line of flow or at the point of discharge. Using a linear motion, a blade advances until the passage is closed, or it withdraws until the passage is open. In the closed position, the knife gate valve is designed to seat tightly and prevent the loss of positive or negative pressure of the system. Aerodyne has a large selection of Knife Gate Valves which can be used to handle a variety of materials and operating conditions. From manual valves to pneumatic valves for dust control, Aerodyne has a knife gate for almost any application.

Since using Aerodyne’s StopTight Knife Gate Valve as part of its bagging process, the company has seen dramatic improvements in the operation. With the ability to control the flow of the fertilizer from the hopper, they have less of a mess to clean up and no longer have a loss of product. The company’s operation is now more efficient and easier for plant workers.

For more information on Aerodyne’s StopTight Knife Gate Valve click the in stock photo above. Or for immediate detailed brochures or a quote click the buttons below.