Bolt Set Selection and Length Calculation

[CADuser47]

Having some trouble with assigning bolt sets to different connections. In my spec I want all flange type joints to use machine bolts and all wafer type joints use stud bolts. Is there a way to automate this? The other problem i seem to be getting is that if I set the bolt part priority to machine bolts and then manually change them to stub bolts after placing a wafer part in the model the length calculation is wrong. The length calculation seems to use the bolt which has the top part priority and isn't done individually. So i can change the bolt from a machine to a stub but the length is too short as the calculation is taken from the machine bolt set.

The images attached show the difference between a flanged joint when a machine bolt is set to top priority and the other when a stub bolt is set to top priority. The correct calculation should show - Machine Bolt = M24x115LG and Stub Bolt = M24x150LG. How do i get both calculations to work separately?

Running on AutoCAD Plant 2022

[Phil-22]

Good morning,

I have not done this myself as bolts are generally frowned on in my industry ... but I would leverage the out-of-box stud-bolt definition. Long answer would be to create and implement your own class which can change between a stud-definition and a bolt-definition ... but that'd be a lot more effort than substituting parts I believe.

Plant3D obviously does not understand what a stud or bolt is. It is merely understanding how to find a piece of information, and transform it based on a algorithm. That algorithm will still work the same regardless whether you call it a stud or a bolt.

In the catalog you would have both your studs and your bolts defined. The Length specified would be the base-length for the part if only two flanges with gasket are connection. You would also have to specify the standard Flange Thickness for each size/rating as the calculation is comparing this to the modelled flange thickness. Stands to reason that for the same size/rating connection that the base bolt-length will be shorter than stud-length.

If the length-increments are different for your studs and bolts, or gaskets differ - you'll want to assign the appropriate Bolt Compatible Standard and Gasket Std as required. If the increments differ you can create your own Bolt Standard (as I did).

You've obviously done this - but both the stud and bolt would be added to your spec with priority assigned to whichever you use most. When the parts are consumed in the model, the algorithm will look at the two flanges, and wafers if present, to determine if a longer fastener is required. Plant3D will not care whether it's increasing a value relative to a "stud" or "bolt". So if your standard is to use a 4" long bolt for a size/rating connection, but a connection introduces a 1" wafer, you may arrive at a 5" long bolt, or 6" long stud (using obviously simple numbers).

This is what I would do. Hope it helps.

[CADuser47]

Thanks for the reply @Phil-22.

I don't have a problem with how the bolts have been setup. When only one is added to the spec by itself it uses the correct length calculation and takes the appropriate value defined in the Bolt Compatible Standard. The issue I am having is when both are added to the spec Plant 3D will not recalculate the length of the bolt when I manually change the bolt set after the part has been inserted. It changes the bolt set but just keeps the length value of the original bolt set. Is there a way to force Plant 3D to recalculate the value?

Running on AutoCAD Plant 3D 2022

[jw7018]

We swap the default from machine to stud for wafer and the calculated lengths hold for me. 

The @@@ seams to keep it at 9 1/4", see below. 

[CADuser47]

Thanks for the reply @jw7018 

What you are showing is the same problem. We don't want the calculated lengths to hold. They need to updated with the corrected calculation, as in the real world studs need to be longer than machine bolts. Seems odd that Plant 3D cant do this.

[jw7018]

I see... We purchase our machine bolts as "sets" (6"-150# machine bolt set - per B16.5) so length only affects the wafer type studs which is calculated as req'd.

Do you use two separate Compatible standards for each bolt type?

https://in-the-pipes.typepad.com/in_the_pipes/2016/07/autocad-plant-3d-handling-bolts-in-piping-spec...

[DACOMA3]

@CADuser47 

As far as I know, the bolt lengths will not dynamically update when you swap the bolt sets in the model. Other properties will update but not the length. You have to manually edit the length.

https://knowledge.autodesk.com/support/autocad-plant-3d/troubleshooting/caas/sfdcarticles/sfdcarticl...

[jw7018]

A terrible workaround would be to change the spec default priority back to studs and delete/re-connect wafers to have the proper bolt/length if manual length corrections is not preferred. Data manager filters could speed this process up.