“Duct Guardian” is a sheet metal program that calculates flat (unfolded) sheet development of ducts, rectangle to round transitions, cylinders, cones, pipe intersections, connections, bifurcations, elbows, etc. For HVAC, hoppers, cyclones, dust extraction, ducts, conveying systems, silos, piping, etc.

Steps of use:

First select the 3D surface you want to unfold.(You can select: either inside, outside, or mid cross sectional dimensions and / or height specifications; to draw or not the 3D surface, and the unfolded sheet as a mesh [to help you when bending the sheet] or as 2D contour [to ease cutting]; the precision of the calculation of the developments).Metric Units / Imperial units: the program automatically sets the units according to the units used in the current drawing session. After finishing the input of parameters, the program draws the 3D object and the respective development.

Some common fittings:  Square to round, Radius branch, Radius offset, Cylinder, Cone:





















– one piece seam calculation

– limited bend position markers

– database sample

– 14 free fittings



Some ‘Duct Guardian’/’DG Nest Pro’ fittings examples and layouts nesting:





Automatic Nesting and Automated Nesting --- Smart Shoppers Know the Difference
Duct Guardian - Radius Elbow +ruters (turning vanes)


  • Commenter's Avatar
    William — August 23, 2016 at 6:56 pm

    I like the idea and it is definitely a product worth purchasing, but I can’t find any link to purchase. Also the free version dxf output can’t be opened by any CAD program I own or have. Would love to have some feedback on this.

  • Commenter's Avatar
    admin — August 23, 2016 at 10:43 pm

    Hi William,

    you have purchase PayPal button on download section (above software images) choose PayPal option (Skrill option is not currently in use).
    Dxf from Duct Guardian can be opened with free DraftSight CAD, CadStd CAD, SheetCAM.
    The reason why you can not open with other CADs is their complex dxf header format requirements.

  • Commenter's Avatar
    William — August 24, 2016 at 10:31 am

    Hi admin, thank you for the reply

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