Downcomer Duct Work with Expansion Joints

Steel duct assemblies have a wide range of uses. Refax, Inc. specializes in ductwork that transfers heavy wear/particulate air as well as gases through any system in any industry.

The downcomer is a series of ducts, elbows, and expansion joints that transfer dirty particulate heavy air and gas from the blast furnace to a process center for disposal and recycling. All ductwork, elbows, and expansion joints were made from formed Chrome Carbide Wear plate cut, formed, fit, and welded at our shop. All welds needed to be ASME gas tight with tolerances of +/- 1/16″. This project had various hold points for inspection with a full final inspection for welds, whole layout, expansion joint movement, and all other various critical items. Once complete we will coat each part with red oxide primer and deliver to our customer.

Project Specifications

Product Description

This duct assembly is used as a downcomer. The primary function of a downcomer is to move gas with a high concentration of particulates. The gas is moved through the downcomers to a dust catcher to further clean the gas of particulates. Because the particulates cause a high amount of wear, the ductwork is made from rolled Chrome Carbide Wear plate. The flanges are machined and pre fit for a gas tight seal.

Capabilities Applied/Processes

  • Burning
    • Cut Plate to Size
  • Rolling
  • Fitting
  • ARC Welding
    • ASME gas tight welds
  • Priming
    • Prime w/ Red Oxide

Overall Part Dimensions


Tightest Tolerances

+/- 1/16″

Material Used

A36 Steel, 1750 SA

In Process Testing Performed

100% Inspection

Estimated Part Weight


Industry For Use


Delivery Location

East Chicago, Indiana

Standards Met

Customer supplied print, 2D CAD Drawing