Move a wide range of material continuously, reliably, and effectively in any direction without dusting.

Tubular Drag Chain Conveyor

Tubular Drag Conveyor - Versatility Meets Durability

Not all drag conveyors are created equal. When your conveying needs are longer distances, unique layout configurations, over multiple levels, requiring numerous inlet and discharge points, with durability for handling abrasive material, or gentle handling for friable material, you need our Tubular Drag Conveyor.

  • Convey product in a completely sealed system. The sprocket drive slowly pulls a heavy-duty chain through a fully enclosed pipe. As the chain moves your material through the pipe there is no chance for dusting, explosions or contamination issues.
  • Use less energy than other conveyors to move powders or bulk solids. The low-horsepower motor produces the slow, steady drag that cuts your energy costs.
  • Move challenging materials. Convey high-moisture ingredients, abrasive, blended, friable, easy-to-compact or smear products without compromising quality or efficiency.
  • One conveyor does the work of several, no problem. Configure your tubular drag chain conveyor to convey your product vertically, horizontally, at any angle and around corners. Need more than one inlet/outlet in your process? Add as many as you need.
  • Modular design allows for optimum conveying, including length, conveyor path, number of inlets or discharge outlets.

next: History

History of the Tubular Drag Conveyor

hapman-buildingHenry Hapman invented the Tubular Drag Conveyor in 1945 in Detroit, Michigan. The concept for the totally enclosed, multi-plane conveyor came from his industrial manufacturing experience as a mechanical engineer. He recognized the need for a conveyor that could effectively move material from point to point when the distance between the two was not a clear path. Mr. Hapman knew as World War II was ending the focus of industrial manufacturing would shift from government to consumer. He saw the Tubular Drag Conveyor as the way to effectively move material the distance of a plant, providing inlet stations and discharge points where needed. The vision of Henry Hapman forever changed the manner in which dry material is moved in industrial production facilities. Over the years, others have attempted to copy the Hapman Tubluar Drag Conveyor, but never creating a true equal. The engineering, design, and material handling experience coupled with the unyielding passion for efficient, reliable operation are the elements that make the Hapman Tubular Drag Conveyor the premium mechanical conveyor of modern manufacturing.

next: Operation of the Tubular Drag Conveyor

The Tubular Drag Operation

The fundamental operation of the Tubular Drag Conveyor is a chain with flights that pull material through a sealed pipe circuit. The conveyor is sealed to upstream and downstream equipment by a hard flange or a flexible sleeve. The layout of the conveyor allows for pipe bends and multiple inlet and discharge points. The Tubular Drag Conveyor can be routed through multiple planes and in any direction. The capacity of the conveyor is determined by the diameter of the flight and the speed at which the chain assembly can be pulled through the pipe The equipment operates as a high torque/low speed.

 All of our Tubular Drag Conveyors are customized to fit your facility needs, including multiple inlet and outlet ports, 90 deg bends and more.

next: Features of the Tubular Drag Conveyor


  • Operate dust-free. Tubular drag’s completely sealed tubular construction confines materials to the process. Convey materials in any direction – horizontally, vertically, at any angle and around corners – without dusting, odors, contamination or spillage.
  • Convey up to 50 cfm (1.416 cmm). A sprocket drive pulls a chain through a stationary outer casing. Flights attached at regular intervals along the chain convey material from inlet points to discharge points.
  • Get longer life from chain than steel cable. Chain is less prone to fatigue, wear and stretch than steel cable. As individual parts on the chain wear out you can replace them at a much lower cost and time expense than replacing the entire steel cable.
  • Work day-in, day-out with minimal chain wear. Heavy-duty chain allows you to start conveyor under load all day long.
  • Discharge 100% of your product. Hapman’s exclusive, self-cleaning discharge gate is rounded to the shape of the pipe so, unlike flat gates, there is no place for your product to get trapped.
  • Requires minimal maintenance. The automatic chain take-up idler makes adjustments as the chain stretches so you don’t have to do regular manual tightening.
  • Eliminate multiple conveyors with multiple inlets/outlets. Install numerous inlets and/or discharge points into a single tubular drag conveyor. Then add ingredients and discharge product all along the way. Tubular construction lets you reconfigure your design as your process needs or floor layout changes.
  • Low-horsepower, electric motor drives material for hundreds of feet using minimal energy.

next: Tubular Drag Conveyor Options


Custom-built systems convey your product effectively and reliably. Hapman's custom-built tubular drag systems move some of the toughest products up to hundreds of feet: hardened steel shot to bacon grease waste to fishmeal and bones to explosive materials. Paths are virtually limitless with multiple inlets and outlets. Our engineers can help you build a system based on your specific applications needs. In addition to optimum conveying, the sealed Tubular Drag Conveyor offers:

  • Process efficiency
  • Clean – Dust Free Plant Environment / worker safety
  • Excellent Material Integrity (degradation / segregation)
  • Low Energy Consumption
  • Minimal Maintenance Requirements
  • Brush Box Cleaning
  • Discharge Gate
  • Auto-Tensioner

Improve product flow-when you install mechanical vibration. An offset weight and hammer system taps on the tops of flights to dislodge material.

Fully discharge material-Hapman’s exclusive, self-cleaning discharge gate is rounded to the shape of the pipe so, unlike flat gates, there is no place for your product to get trapped.

Detailed Options

Hapman Auto Tensioner

next: Tubular Drag Conveyor Specifications


Chart demonstrates average capacity in cubic feet/minute based on pipe size and the optimum speed of the chain assembly moving through the conveyor

Tubular Drag Conveyor Size Specification Chart

Pipe Casing Diameter & Material Options
3 in (76 mm) to 12 in (300 mm) diameter
Carbon steel
Stainless steel

Chain Material Options
Carbon steel
Stainless steel

Circular Flights
Cast iron
Ductile iron
Stainless steel
UHMW polyethylene
Tivar® H.O.T. premium UHMW polyethylene

Maximum Conveyance Distance
85 ft vertically (26 m)
400 ft horizontally (122 m)

Convey up to 50 cfm (1.416 cmm)

next: Right Chain and Flight Assembly

The Importance of the Right Chain and Flight Assembly

You never have to worry about selecting the right chain and flight assembly for your application because we will work with you to determine the optimum assembly for your needs. We do not believe in a one-size fits all approach to conveying material. Our more than 60 years of experience supports and our testing of over 2600 materials confirms, mechanical conveying is most effective when the right combination of chain type and flight material are applied to the material characteristics of the conveyed material. This is why we offer the most comprehensive array of chain and flight options in the industry.

We offer the wide range of chain and flight options to provide you the best conveying equipment for your application. The options range from:

iPhoto Library 4  

Sealed pin chain



  • iPhoto Library 2Sealed pin
  • Universal sealed pin
  • Drop rorged or rivet-less chain
  • Round link






Flight material options range from UHMW Polyethylene, glass reinforced Polyethylene, cast steel, and iron. Each of which offers exceptional conveying properties when evaluating, bulk density, temperature, and other handling and material characteristics.

  • Cast iron
  • Ductile iron
  • Nylon
  • Stainless steel
  • UHMW polyethylene
  • Tivar® H.O.T. premium UHMW polyethylene



The most common chain and flight assembly is the sealed pin with UHMW Polyethylene flights. The configuration of chain type and flight material provides the longest life of the flight and least maintenance for the chain in most material conveying applications. The sealed pin chain is engineered specifically for moving dry material of various size and bulk density. The main advantages are:

  • Sealed Pin keeps gritty, abrasive material out of the chain knuckle, thus reducing the need for frequent maintenance and significantly extends the life of the chain
  • UHUMW is cost-effective, light-weight, has excellent release properties, is low cost, and has a high wear resistance coupled with a low friction/drag. Each of these properties provides optimum conveying, low horsepower requirements, and low energy consumption


Our wide array of chain and flight options. Each is engineered to provide optimum conveyance of material.

Chain vs. Cable - Learn More!