Autodesk Fabrication: Reduce Workload with Specifications/Pressure Classes – Part 2
28 June 2019All, autodesk, Fabrication

There are many benefits in using Autodesk Fabrication software when you take the time to set up your specifications (pressure classes) for all ductwork. With a little work up front, your firm can see greater cohesion among departments, confidence on fittings input, and overall consistency in what is pushed to the shop floor.
Typically, a user takes the company standards for ductwork and enters this information into their software manually. This allows you to maintain a solid foundation for reducing the workload for all users.
For the first steps in setting up specifications, see the Part 1 article at “Autodesk Fabrication: Reduce Workload with Specifications/Pressure Classes.”
Be sure that you have taken the time to review internally that your specifications/pressure classes are up to date with exactly how the manufacturing side operates. Ensure that the correct connections are used for proper notching – that the shop doesn’t have unique instances where they utilize a seam for fittings that fall outside the standards your company has on paper. Once everything is on the same page, then entry data can be filled with confidence. At that point, it’s onward to inputting entries as follows.
Right click in the white table area and select New, prompting you to input a new entry:

From here you can set the options for the specific size breakpoint that starts out your pressure class. In the example, this will be any fitting less than or equal to 12 inches on the longest side.
- <=Dim: Sets the highest size that fittings will take on this set of information, in this case 12 inches.
- Gauge: Desired metal thickness for this breakpoint.
- STD Straight: Default length of standard straights (typically 60, but specification dependent).
- Connector (In): Specifies the input connector, or connector 1.
- Connector (Out): Specifies output connector, or connector 2; can keep at “Not Used” if connector-out matches connector-in.
- Seam: Specifies the seam for ductwork at this size breakpoint.
- Stiffener: Specifies what stiffener/tie rod setup is applied at this breakpoint.
- Spacing: If set to Stiffen by Spacing, applies the spacing value for your stiffeners; if set to Stiffen by Qty, this field is changed to a quantity value.
- Supports: Specifies the supports used for ancillary reporting.
- Spacing: Sets spacing of supports for accurate ancillary account.
- Sealant: Applies any particular duct sealant.
- Splitter: Applies specific splitters for radius fittings at this size.
- Airturn: Applies specific turning vanes for square elbows at this size.
At this point, put in your first breakpoint at 12 inches (which in the example 2WG pressure class has a gauge of 26), a Slip and Drive connection, a Small Pittsburgh seam, and a standard straight of 60 inches with no reinforcement. All that’s needed is to set the Gauge to 26, the STD Straight to 60, Connector (In) to S&D, leave Connector (Out) to Not Used, and your seam to S-Pits. Once finished, click OK, and your first entry should look something like this:

Go down the list of your pressure class and continue to add more entries. To add another entry below your current one, right click in the white space, and select New. As more and more entries are added, you can see how the table begins to fill out . . .

. . . until you have a final product with all values entered:

Now that the entire thing is built, how is it applied to our items? Two ways: either directly on the item itself during input or through the utilization of services. If your company uses services, you’ll want to go to the main Database->Fittings->Takeoff->Services section. Find the service you want to apply the specification for, then select your specification from the drop down. Any item input with this service will automatically have the specification applied.

To apply the specification on an item outside of a service, when it is being input, under the Item tab, select the specification from the drop down:

Any item you now input should pull connection, seams, and reinforcement from the specification you built automatically.
But what about those Alternate Connectors and Alternate Seams? If you look at the specification again, after creating the Test Conn alternate connection and Test Seam alternate seam, two new columns were added to the specification. For this instance, apply a different connector under the Test Conn column and a different seam under the Test Seam column.

So now there is a specific TDC Cap connection and 1” Lap seam that can be used as alternates. To utilize these alternates, you must note the name you chose for the alternate column. In this case the column names are Test Conn and Test Seam. To apply these changes, you’ll want to find the item that will be using these alternations. Find the item you want to change in your folders, right click on it and select Edit. From there go to the connections. In the space for connections you should see an Alt column. Type in the space below Test Conn in the connection category and Test Seam in the seam category.

Click Accept. Now any time that fitting is added to a job and has this specification applied, instead of looking at the main connection/seam locations in the specification, it will default to the alternate category that has its specific callout (Test Conn, Test Seam). Just make sure you name it exactly as it appears in both the item and the specification.
There will be varieties between your specifications. Some will need the additional length breakpoint, some will utilize the small sides, and others might be broken out by fitting type. However they are built, they follow the same general principles as outlined above. It takes time to fill out your specifications, but for consistency and insuring users are inputting the right data, the time is well worth it.
If you’d like to learn more about Autodesk Fabrication products, contact the industry-trained experts at Applied Software. They’ll show you how to achieve greater unity among departments, confidence in your project data and consistency in what goes to your shop floor.