Common Challenges: Material Characteristics

materials testing

Common Challenges: Material Characteristics

One of the biggest factors in choosing the right conveying system for your product and in the overall design of this equipment is understanding your material’s characteristics. Your product may seem like an easy material to the naked eye but it could be explosive, corrosive, hygroscopic or abrasive. All of these factors will have a significant impact on the equipment your process needs.

Material characteristics:

Flow Characteristics: Is your material sluggish or free-flowing? How the material behaves when it has been conveyed or unloaded is a primary concern when we design your equipment. If your product is sluggish as it is conveyed or it bridges then additional flow aides may be necessary. When we do a materials test we can understand the particular flow characteristics of your product which will help us to recommend the best equipment for your process.

Abrasion: Is your material abrasive? If it is then understanding how abrasive it is will influence what material your conveyor will be made from. When designing your equipment we want to ensure it has a maximum lifespan which we will do by reducing contact points.

Temperature: Temperature can apply to a variety of things such as material temperature, temperature while conveying & the ambient temperature in your facility will all affect how your material behaves as it is processed. This will all have an impact on how the equipment is designed for your process.

Materials Test and Machine Trials

The best way to avoid any future problems caused by your material’s characteristics is to do a materials test followed by machine trials.

At Spiroflow have a test lab where we will conduct testing on your product to analyze the specific characteristics which will help to avoid any future issues and plan which equipment and aides will be necessary for your production. We also have our test facilities are fully equipped with flexible screw, aeromechanical and tubular drag conveyors, as well as bulk bag fillers and bulk bag unloaders, so we can advise without bias on the right type of solution for your particular product, application and layout restraints. Wherever possible, we simulate your site conditions in terms of conveyor length, flow rate and angle of lift. We have a database of product conveying trials logged over forty-five years, taking the guesswork out of assessing flow rates and expected performance. If you are not able to witness a trial, we can send you a video with a full test report and recommendations.

Spiroflow test materials

Get In Touch

To book a materials test or to discuss, your materials specific characteristics with an engineer fill in our Contact Us form.

Structural drag chain conveyor manufacturers want their products to be ultra-heavy-duty problem solvers for the dry bulk solids and powder processing industry. Our team at Spiroflow is no different. We believe in what we design and ship to our customers. Our company has been offering dry bulk solids and powder processing solutions for more than 45 years in countries all over the globe. We know what makes a supplier reliable and respectable.

Searching for a reputable structural drag chain manufacturer can be difficult. So, I wanted to provide a list of manufacturers if you feel a structural drag chain conveyor is the missing piece of your process.  We always want a customer to get the help they need, whether they choose to buy from us or someone else.

Why is a Structural Drag Chain Conveyor needed?

The biggest positive from this type of conveyor is its workhorse-like quality. The conveyor can handle a wide a range of materials and is adaptable to most applications. The conveyor is dust-free and can operate in three planes. Our version, the Dynaflow®, has a total circuit length of 400 ft (120 m). That’s 200 ft (60 m) out and 200 ft (60 m) on the return. More than one conveyor can be linked to span greater distances. Structural drag chains can be equipped with multiple inlets and outlets. They can also be metered or flood fed.

Structural Drag Chain Conveyor Manufacturers


Hapman is based in Kalamazoo, Michigan in the United States with other locations in Poland, China, Brazil, and India. We find that most of their installations are in the United States and Europe. They focus on quality and a comprehensive approach to bulk material handling challenges.


Schrage has been around for more than 20 years and is headquartered in Friedeburg, Germany. Just like other manufacturers, Schrage is committed to helping processors convey materials from point A to point B. The company’s philosophy is to deliver the best solution for their clients.

Here’s What We Can Offer You

Thank you for checking out this post. Honesty is a priority for us here at Spiroflow. That includes conversations in person, over the phone, through email, and in this blog. I hope you feel you can turn to us with any structural drag chain conveyor questions or needs.

Do you want to see a structural drag chain conveyor in action? We have test labs in the United States and the United Kingdom. Give us a call and we’ll set you up with a material test. You’re invited to witness the test in person or we can record the test and send you the video. Running a test is the best way to see if this conveyor is correct for your process.

I’d also like to mention that we have an extensive line of dry bulk solids and powder processing equipment that we can supply or help you with. We design bulk bag fillers and dischargers as well as several other types of mechanical conveyors. Are you looking for a control systems integrator? Our team can do that as well.

What are the best materials for a structural drag chain conveyor? These conveyors are problem solvers in a pipeline. That’s our nickname for them and there’s a good reason for that. If there’s a material or product that won’t convey well in another type of conveyor, an ultra-heavy-duty structural drag chain conveyor built with schedule 40 pipe will likely get the job done.

At Spiroflow, we have more than 45 years of experience providing processors with the best conveying solution possible. We know how important your product is to your bottom line. Running the wrong type of material inside a conveyor can cause damage to the equipment and result in system downtime. That isn’t much of a concern with these conveyors.

Where do structural drag chain conveyors fit in a process?

You’re not locked into one type of layout with structural drag chain conveyors which are called Dynaflow® conveyors in our product line. These dust-free conveyors can operate in three planes which means processors have very flexible layout options. Our conveyors have a total circuit length of 400 ft (120 m). That’s 200 ft (60 m) out and 200 ft (60 m) on the return. Multiple conveyors can be linked together to cover longer distances.

These conveyors can have multiple inlets and outlets and can be metered or flood fed. And, of course, structural drag chain conveyors can operate seamlessly with bulk bag fillers, bulk bag dischargers, other conveyors, and other process equipment.

Ultra-heavy-duty Construction

What are they made of? Structural drag chain conveyors earn their label as ultra heavy-duty process equipment. The conveyors are built with schedule 40 steel pipe and steel chain fitted with UHMWPE or steel discs.

Speed & Capacity

Conveyor speeds will vary depending on the size of the pipe and material you are running. Conveying speeds can reach up to 50 ft/min (15 m/min) and capacities typically reach 10 ft3/min (0.28 m3/min). Operators always have the option to run the conveyor at slower speeds if there’s concern over product degradation.

Best Conveyed Materials

Drag chain conveyors operating within the confines of a pipe are the workhorses of the bulk material handling industry. They are almost a catchall in the conveying world. Here’s what I mean. Sludge-like materials won’t convey well in a flexible screw, cable drag, or an aero mechanical conveyors but they will convey nicely inside a structural drag chain conveyor. This is also the case with cohesive and abrasive materials. Basically, anything considered a heavy-duty material. I could list out all of the conveyable materials for you but there’s too many to mention in this blog post. Here’s a list of material characteristics that will likely work:

  • Dry
  • Fragile
  • Abrasive
  • Hygroscopic
  • Moist
  • Cohesive
  • Hot up to (420˚F/216˚C)
  • Sludge

There are some types of products that should stay out of these conveyors. Fine particles aren’t recommended and I recommend material testing for slurries. The construction of structural drag chain conveyors also doesn’t lend itself to sanitary applications. So, ideally, food products should be kept out of these conveyors. I should note that running a material test is important no matter what product you’re planning to convey.

The Value of a Material Test

If it seems like a structural drag chain conveyor might be useful in your application, call a trusted manufacturer and run a material test. This is an important step in the design process. Everyone involved wants the installation and execution of your project to be successful. Utilizing a test lab is a great way to make sure this happens.

Other Conveying Options

A structural drag chain conveyor is a serious investment. They are among the most expensive conveying options out there. In some cases, other conveyors can do the same job at a lower cost. A reliable manufacturer with expertise in many different mechanical conveying technologies can make a recommendation to you based on your application requirements.

Do you want more information?

Give us a call or send us an email if you have any questions. Our experts are happy to help you with your mechanical conveying, bulk bag filling and discharging, or control systems integration needs. Also make sure to check out our blog “What materials are best conveyed by Drag Chain Conveyors?”


Different applications need different drag chain conveyor types. We’re here to help make sure you choose the right drag chain system for your application. We’ve been in the bulk material handling industry for more than 45 years and have designed and sold all types of drag conveyors and drag chain conveyor systems over the years.

Choosing the correct drag chain conveyor type means you’re not spending more money on a conveyor you may not need. It also means you’re getting a conveyor that can handle your product without concerns of mechanical failure or system downtime. Everything you need to know is right here.

Drag Chain Conveyor Types

I want to take a second to define exactly what I’m talking about. The differences between structural drag chain conveyors (ultra-heavy-duty) and tubular drag chain conveyors (heavy-duty) are easy to spot. From the exterior, you can see that structural drag chain conveyors are built with schedule 40 pipe. Tubular drag chain conveyors are often built with stainless steel tubes.

The differences are easy to spot inside the conveyor too. Structural conveyors have stainless steel or cast iron chains with UHMWPE or steel/iron discs. The non-structural conveyor has a stainless steel chain with molded on UHMWPE discs.

How drag chain conveyors and systems are built determines what kind of materials can be passed through them.

Drag Chain Conveyor Types: Differences in Conveyable Material

The material you’re looking to convey is one of the biggest determining factors for what conveyor you need. This is a topic we’ve written about before when every type of conveyor is being considered. I’m just focusing on drag chains here. Any product a tubular drag chain can convey, a structural drag chain convey. That rule doesn’t apply going the other way.

Structural drag chain conveyors can handle virtually any type of bulk material but these aren’t recommended for hygienic applications. It’s worth noting that these conveyors run much slower than other types, so it is important to understand their maximum rate and capacity compared your desired rate & capacity (more on this below). These types of conveyors are much more expensive than the drag chain alternative.

Tubular drag chain conveyors aren’t as much of a workhorse, but they are effective when it comes to a variety of materials. Dry, cold, hot (up to 180˚F/82˚C), powders, and granules are ideal for the conveyors. Sludge, slurries, moist, and cohesive materials should typically be avoided. Another blog posts details what should and shouldn’t be conveyed in a chain drag conveyor.

Drag Chain Conveyor Types: Speed, Capacity & Length

Structural drag chain conveyors can run up to 50 ft/min (15 m/min) with a capacity up to 10 ft3/min (0.28 m3/min). A conveyor’s maximum total length is up to 400 ft (120 m) and multiple conveyors can be linked together.

Tubular drag chain conveyors can run up to 100 ft/min (30 m/min) with a capacity up to 6.2 ft3/min (0.18 m3/min). The total length is up to 500 ft (152 m). These conveyors can also be daisy chained.


Cleanability is a topic that comes up whenever we work with a customer. It might be your number one priority depending on your application. So, I thought I’d address it here.

Structural Drag Chain Conveyor Cleanability

These conveyors aren’t designed or recommended for hygienic/sanitary applications. They can be cleaned using a cleaning media in non-sanitary applications.

Tubular Drag Chain Conveyor Cleanability

This type of conveyor is ideal for hygienic applications with its crevice-free chain and disc assembly.

Sanitary Applications

  • Food products are common applications requiring a very low microbial count.
  • The chain can be removed for cleaning and dried remotely.

Non-Sanitary Applications

  • The conveyors can be cleaned by dry scouring (running an abrasive product) or air purging.
  • Scavenged dust is directed out through a discharge outlet.
  • They can also be wet washed and drained.
  • The chain can be removed for cleaning and dried remotely.

Drag Chain Conveyor Types: Maintenance Differences

Proper chain tensioning is crucial for any type of drag conveyor regardless of its construction. Be sure to ask the manufacturer about auto tensioning options.

Use a Test Lab

Anyone with experience in the dry solids and powder processing industry can tell you what likely will or won’t work for an application. The only way to know for sure is to utilize a test lab. Spiroflow has test labs in the United States and the United Kingdom. I can tell you from experience that fine-tuning a piece of equipment is much easier in the testing phase than post installation.

Do you have any questions?

Are there any questions we didn’t answer? Let us know. Give us a call or send us an email. A member of our team will be more than happy to help you out. Are you interested in more than just drag chain conveyors? We have an unparalleled line of process equipment and we also do control systems integration.

How much does a structural drag chain conveyor cost? They aren’t inexpensive compared to other mechanical conveyors but they deliver under the most extreme conditions. The exact price depends on your layout and application parameters, but it can be worth it. These conveyors are ‘problem solvers in a pipeline’!

This article is for processors who want to understand the cost of using a structural drag chain conveyor in their process. If this conveyor fits your needs, the price is completely worth it. If it’s not a good fit, there are several other conveying solutions available. By the end of this article, you’ll know which direction to go in.

What is a Structural Drag Chain Conveyor?

I want to give you a clear picture of what specific conveyors I’m talking about before I go any further. Not to be confused with tubular drag chain conveyors, this article is about conveyors utilizing a chain assembly inside of a structural pipe. Here at Spiroflow, we refer to them as Dynaflow® ultra heavy-duty conveyors.

Cost Elements of a Structural Drag Chain Conveyor

These conveyors are powerhouses compared to other mechanical conveyors. They don’t move material quickly, but they can move the widest variety and most difficult materials.


The material used in your application, along with the conveyor size, layout, speed, and capacity, will directly impact the drive assembly and motor required. Motors range from 1/3 HP up to 30 HP.


Structural drag chain conveyors will successfully convey the most challenging of materials such as sludge. See a partial list of materials here. Consider this type of conveyor if your process requires you to convey:

  • Very hot materials – temperatures up to 420˚F (216˚C)
  • Fragile materials
  • Blends
  • Hygroscopic materials
  • Moist materials
  • Cohesive materials
  • Sludge
  • Slurries
  • Fine particles

Conveyor Speed

Conveyor speeds are typically up to 50 ft/min (15 m/min) and capacities typically reach 10 ft3/min (0.28 m3/min). Conveying rates are variable. Operating the conveyor at slow speeds minimizes the risk of material degradation.

Conveyor Size

Structural drag chain conveyors from reliable suppliers are usually offered in a variety of sizes (pipe diameters) to meet specific application dependent requirements. At Spiroflow we offer 3”, 4”, 6” and 8” conveyors. Of course, larger conveyors will provide higher capacities.

Conveyor Length & Layout

Structural chain drag conveyors can be laid out in a variety of configurations such as straight runs, loops, ‘Z’ configurations, and bulb loops. Of course, the length and layout of the conveyor will impact the price. An expert manufacturer can make recommendations on the ideal layout and then calculate the cost of the required length, the number and degree of bends and type of idler assembly.

The conveyor’s maximum total length is 400 ft (120 m) which includes the return leg. Multiple conveyors can be linked together to cover greater distances. The conveyors can have multiple inlets and/or multiple outlets.

Materials of Construction

Pipe: At Spiroflow, our drag chain conveyors are built with your choice of structural pipe.

  • Schedule 40 carbon steel pipe
  • Schedule 40 304 stainless steel pipe
  • Schedule 40 316 stainless steel pipe

Chains & Flights: We can recommend the optimal type of chain for your application in 304 stainless steel, 316 stainless steel or cast iron. Chain choices include:

  • Sealed pin chain with black neoprene seals & UHMWPE flights
  • Sealed pin chain with white nitrile seals & UHMWPE flights
  • Sealed pin chain with high-temperature silicone seals & carbon or stainless steel flights
  • Dropped forged chain with cast iron flights

Flange Joints: There are a variety of flange joints to choose from. Not sure what you need? Don’t worry. We can make a recommendation based on your application.

  • Carbon steel flanges, black neoprene gaskets & grade #5 fasteners
  • Carbon steel flanges, white nitrile gaskets & grade #5 fasteners
  • Carbon steel flanges, high-temperature silicon gaskets & grade #5 fasteners
  • 304 Stainless steel flanges, white nitrile gaskets or high temp silicone gaskets, & stainless steel fasteners

NOTE: If your application requires different materials of construction a knowledgeable manufacturer should be able to offer additional alternatives.

Additional Options

Structural drag chain conveyors can be provided with a variety of additional options which may be recommended based on your application. These include but aren’t limited to:

  • Flanged discharge hopper
  • Air actuated discharge gates
  • Inspection ports so operators can monitor the chain and material moving through the circuit
  • Chain vibrator at discharge so material is removed from the surfaces of the chain
  • Control system to operate the conveyor

Other Structural Drag Chain Benefits

  • Totally enclosed, dust-free, contamination-free handling
  • Operation in three planes
  • Medium energy consumption
  • Very low maintenance costs
  • Can be started and stopped under load
  • Can be run e­­­mpty

Structural Drag Chain Conveyor Cost

Now, let’s talk about how much what this all adds up to. The price will vary depending on your layout, materials of construction, conveyor size, specifies rates and capacities as well as elected options. A basic conveyor build will cost about $20,000 (£16,500). A complex design will cost $200,000 (£165,000).

Other Conveying Options

I mentioned this at the top, but if you think a different conveyor would be a better fit for your process, give us a call. Some conveyors can do the same kind of work for a much lower price. Here at Spiroflow, we have decades of experience in the dry bulk solids and powder processing industry. We’ll help you find the conveyor for you.

Need more?

We have you covered if you have questions or if you’re interested in adding more than a structural drag chain conveyor to your process. Check out our line of bulk bag fillers and dischargers. Let us know if you have any questions about them.

We also perform control systems integration. Again, if you’d like to know more, feel free to ask.

Don’t Forget to Run a Test

One last thing, I highly recommend running a material test when considering any type of conveyor. Past projects give us a good idea of what will and won’t work. Using a test lab is the only way to know for sure. This allows you to see how the conveyor will run using your product. It’s so much easier to fix problems in the testing phase versus post installation.

Cable drag conveyors will gently handle the material fed into it. The key, however, is to make sure the proper material is being used. Selecting the wrong type of material to move with a tubular cable drag conveyor can lead to an inefficient process and machine downtime.

Our team at Spiroflow has been helping processors with their conveying needs for more than 45 years. Whether you’re a customer or not we want to help.

Where do Cable Drag Conveyors fit in a process?

There are several ways to install a cable drag conveyor depending on your layout needs and process. For example, Spiroflow’s conveyors have a total circuit length of 400 ft (120 m). Multiple conveyors can be linked to span greater distances.

The conveyors can have multiple inlets and outlets. Cable drags can also be metered or flood fed. This conveyor’s flexibility means it can work effortlessly with bulk bag fillers, bulk bag dischargers, other conveyors or other process equipment in your system.

Cable Drag Conveyor – Best Materials

Cable drags can run while empty. They can also be started or stopped while under load. But, what should and shouldn’t be conveyed?

Any respectable manufacturer will suggest running a material test to determine if your conveyor of choice will get you the results you’re looking for. We’ve learned that problems are much easier to solve during the testing phase compared to after the conveyor is installed.

Materials Effectively Conveyed

  • Dry
  • Fragile
  • Hot (up to 180˚F or 82˚C)
  • Fine particles (good on dry granules, ideal for cereals, nuts, coffee beans)

Not Suitable for Cable Drags

  • Abrasive
  • Hygroscopic
  • Cohesive
  • Slurry
  • Sludge
  • Large particle size


Cleanability is among the top concerns of processors we work with. Fortunately, there are several cleaning options processors can utilize with cable drag conveyors.

Manufacturers can offer hygienic construction materials, a sanitary finish, and air purges and spray nozzles in housings. One thing no manufacturer can guarantee is a sanitary braided steel cable. A coated cable may be possible depending on the application, but it’s important to note that the coating may come off over time. The braided cable has crevices and material can be trapped in the threaded steel. It’s another reason why matching the conveyor to your process and material is so important.

The cable can be removed for cleaning and the rest of the cable drag conveyor can be cleaned by dry scouring (running an abrasive product) or by air purging. Scavenged dust is directed out through the discharge outlet. Adding a wash gate and drain will allow the conveyor to be wet washed.

Other Conveying Options

Hopefully, you now have a better idea if a cable drag conveyor is a right fit for your process and material. If a cable drag won’t work for you, there are plenty of other conveying options. Based on your application requirements those alternative solutions might include ultra-heavy duty structural drag chain conveyorsheavy-duty tubular drag chain conveyorsaero mechanical conveyors, or flexible screw conveyors. We can always evaluate your process needs and make a recommendation to you.

Run a Material Test

If a cable drag seems like a good fit, I suggest running a material test. I mentioned this before, but it’s important. There are hundreds of materials that can be conveyed in a cable drag conveyor. The only way to know for sure that a material will work for your process is to test it out.

Want more information?

If you have any more questions, give us a call. Spiroflow has been a leader in the bulk material handling industry for four decades. Anyone of our experts will be happy to help you out. We’ll do everything we can to help you find the right bulk material handling solution.

We don’t just design and supply cable drag conveyors. Feel free to check out our entire line of conveyors, bulk bag fillers and dischargers, and what we can offer you from a control systems integration perspective.