Tubular Drag Conveyors

A Quiet and Reliable Performer

Selecting the right conveyor for a particular need is an important decision but it need not be a daunting task. Across the broadest spectrum material compositions, flow behaviors and special characteristics, one conveyor checks more boxes on the plus side of the balance sheet than any other – the Hapman Tubular Drag Conveyor. For over 70 years, this tubular conveyor has moved everything from A to Z, in markets that are nearly as many and varied as the materials themselves.

Whether handling powders, granules, fibers, or friable clumps, whether sluggish or free flowing, hot or cold, wet or dry, mild or abrasive, inert or reactive, Tubular Drag Conveyors can be found performing quietly and reliably.

Image of Hapman tubular drag conveyor in a Z-style configuration

Advantages of the Tubular Drag Conveyor

Zero Dust Emission.​ The Tubular Drag Conveyor’s totally enclosed, dust-tight design makes it an obvious candidate for handling and containing dusty, smelly, toxic, or even hazardous materials.

Conveys Vertically. In crowded plant environments, the ability to convey vertically is a game changer. Suddenly retrofitting a vital new process into the middle of the plant is made possible by a conveyor that can receive material and immediately turn upward, conserving valuable floor space.

Eliminates Multiple Conveyors.​ What has traditionally required two or three conveyors can often be accomplished with just one Tubular Drag Conveyor. The ability to convey through bended pipe makes it possible to route conveyors through layouts requiring changes of direction.

Start/Stop Under Load.​ This conveyor is a high-torque/low-speed device. Not only does this mean it is very energy efficient, using less energy than other conveyor types but it allows them to stop and re-start while fully loaded.

Gentle Handling. ​Product captured between flights is moved en masse exposing it to very little turbulence during its transfer. Only a small percentage is ever in contact with the pipe wall minimizing the potential for abrasive degradation.

Standard Features

Image of 3 tubular drag conveyor configurations by Hapman

Many Layout Possibilities
There are a dozen or so basic layouts but the customization of those, particularly to leg lengths and bend angles is practically limitless. This enables the Tubular Drag Conveyor to meet the unique demands of every layout. Our expert application engineers and designers will work with you to discover the most efficient layout for your specific needs.

The following are examples of some of the more common layouts:

Pipe and Flanges

Heavy Duty Pipe and Flanges
Hapman’s standard construction consists of heavy schedule 40 pipe (sch 80 optional) with slotted round flanges, continuously welded and offset in a way to create male and female ends. The heavy pipe wall not only lasts longer than thinner walled pipe but provides an added measure of structural rigidity that aids in its own support. The slotted flanges allow components to be rotated for ease of alignment, meanwhile providing a secure joint that will not separate.

By comparison, other manufacturers commonly supply light duty sch. 10 pipe with compression couplings instead of flanges. Lighter gauge pipe wears out faster and may require shorter spans between and thus a greater number of supports. Couplings are a less secure method of joining pipe and can allow joints to separate leading to product leakage and premature flight wear.

Multiple Chain & Flight Options

Sealed Pin Chain & UHMW Flights

Sealed pin chain is the most universally applicable as it is used for handling the widest range of material types, from gritty abrasives to food stuffs. Unlike open-architecture types, this heavy duty engineered chain utilizes sealing washers to keep material out of the articulating aspect of the chain, which can be extremely beneficial when handling certain products.

Rivetless Chain & UHMW Flights

Our first choice for many applications, this rugged, dependable drag chain performs exceptionally well in situations where an open architecture chain can be applied.

Rivetless Chain & Cast Iron Flights

Iron flights are one example of alternative flight types we offer, to overcome specific challenges such as elevated temperatures.

Uni-Seal Chain

These additional chain options give us the ability to custom engineer our tubular drag conveyors for a wider array of applications. They also offer superb reliability in demanding industrial environments and any situation where uptime is critical.

Round-Link Chain

Nearly all Tubular Drag manufacturers offer the Round-Link chain, most to the exclusion of all other chain types. The reason is primarily due to its availability and relatively low cost as compared to engineered chains. As logic would suggest, round-link chains have their limitations but, in some instances, a round-link chain is “good enough.” However, customers expect more from Hapman and we value that reputation, so we are far less likely to recommend it.

See why Engineered Chain is better than Round Link.

Hapman provides several options to customize the tubular drag chain conveyors for your particular operational or process needs.

​Self-Cleaning Discharge Gate
Our rounded gates conform to the pipe so there is no place for your material to become trapped.

Chain Hammers

Chain Hammers
An impact shoe assembly attached to the free end of the spring projects through a seal inside the conveyor and into proximity with passing flights (pucks). When energized, movement of the spring plate causes the impact shoe to reciprocate, striking the flights with enough frequency and amplitude to dislodge materials that may otherwise have a tendency to stick to the chain.

Brush Box
Often used in addition to chain hammers or air knives and usually at the last discharge points, brush boxes can provide an added measure of flight and chain cleaning to minimize problematic material build up and carryover. These have also been incorporated into schemes utilizing washing, rinsing, and deodorizing.

For some applications the layout of the conveyor, or the lack of maintenance availability, can create a scenario in which the conveyor’s chain tension is not monitored and adjusted as needed. This could create a potential problem. For this the answer is the Auto-Tensioner. This air-over-hydraulic automatic tension system provides consistent pressure to make sure that the chain is at its optimum tension. When it is time for manual intervention a notification will be sent.

Clean In Place

As may be required by various plant equipment cleaning protocols, Hapman Tubular Drag Conveyors can be cleaned-in-place. This can be done in one of two ways. The first is that we can supply tubular drag conveyors conveyors which are CIP-ready, which is to say they are inclusive of all the features such as nozzles, supply valves, drain valves, isolation valves and connections necessary to integrate with an exciting CIP system. The second is a more comprehensive approach wherein Hapman also supplies the tanks, pumps, valves, and PLC controls.

Rate Chart

Conveying Rates
The chart above represents the optimum convey rate for most bulk materials based on average capacity in cubic feet/minute and pip size. Actual capacities vary depending on the material type, its abrasiveness and flow character.

Have technical questions about our Tubular Drag Conveyors?

Eric Smith

Product Specialist

(269) 382-8238

Email Me

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