Pipe outer diameter vs nominal diameter

In OpenBuildings Designer you can model pipes on the basis of the outer diameter value.

To better ilustrate the problem:

I would like to be able to model the pipes with real outside diameter in 3D. Is this possible?

Hi Pedro,

If the pipe is based on a nominal size + schedule rating to determine wall thickness I'm not sure you can change the method since that's how the manufacturer would supply the pipe.  If so, is there an alternate catalog that provides the components you need?  

The only alternative I can think of would be to directly add rows to the applicable MDB file (using MS Access) for those pipes where the actual OD is what you need, and the schedule rating works inward vs. outward... if that makes sense.  Or create a new MDB with just the components you need (can otherwise match an existing catalog MDB).  While a bit old, this Wiki outlines steps for creating a custom MDB: https://communities.bentley.com/products/building/building_analysis___design/w/building_analysis_and_design__wiki/10910/creating-a-custom-manufacturer-s-catalog-for-plumbing-components

Hi Steve,

The catalogues are fine, they even have all the information needed (nominal diameter and outer diameter). It was just a matter of having the pipes modelled with the true size (outer diameter) instead of the nominal. This is still ok for most of the work, but it would be good to have the option.

Hi Pedro,

a few weeks ago I had the same question in SR7000901643 the Support.

In my opinion the system creates wrong geometrically piping sizes.

My question was:

If I use the Catalog en-pipesandfittings in End Spec 1_2 ParameterDiameter 1 I can enter only enter a nominal width e.g. 100.
This nominal width of pipe has an outer diameter of 114.3mm.
But the 3Dmodel of the pipe is created with an diameter of 100 mm!
This is wrong! For example, apipe with nominal width has an outer diameterof 114.3mm and an minimum inner diameter 107.1mm.
The nominal width size is no real size!

I got this answer from Support:

We, in AECOsim Building Designer/OpenBuildings Designer, use nominal diameter for all kinds of pipes in all datasets. We do not consider the thickness in the graphics, but that information is always considered in the business data or report that you might generate from your project. If you have different ODs for a single nominal diameter, you have the option to add it in the manufacture catalog and choose that pipe from manufacture catalog during modelling.

I would like to choose pipe sizes by nominal diameter, but it should create a pipe with real size.

But it seems that this isn't possible.

Regards,

Christian

Hi Christian,

Yes, that's exactly it. I think the idea behind is to mimick 2D traditional workflows where, a lot of the times, piping is drawn with nominal diameter. And I think for most parts of the design it is probably enough. It would still be good to have the option to change this (without having to "trick" the software). It doesn't seem that hard since the information is already in the dataset. It could even be just a button or switch, to change the graphics from nominal to outer diameter.

Regards.

Hi Christian,

Yes, that's exactly it. I think the idea behind is to mimick 2D traditional workflows where, a lot of the times, piping is drawn with nominal diameter. And I think for most parts of the design it is probably enough. It would still be good to have the option to change this (without having to "trick" the software). It doesn't seem that hard since the information is already in the dataset. It could even be just a button or switch, to change the graphics from nominal to outer diameter.

Regards.