Nominal Spec and Spec?

[darrelldixon]

Can someone explain the difference between the two fields "spec" and "nominal spec"?

[quentin.contreras]

In Plant 3D a "Spec" refered as when you are routing pipe and adding pipe fittings or valves to a model, you start with a pipe spec.

A 3D piping model is spec-driven; it references piping components listed in a pipe spec. When you work with piping in a 3D model, the pipe spec provides the material, rating, and connection details.

Spec files are created using the Specs and Catalogs Editor. For more information about pipe specs, see Introduction to Specs and Catalogs.

In combination with the project joint settings, the pipe spec determines which fittings and fasteners are used when connecting and routing pipe. For example: it specifies the socket weld fittings for pipe under 3”. Each pipe segment and fitting in the model originates from a pipe spec, except for custom parts.

I am not clear where exactly you are refering to the nominal spec. Is this in reference for the Property Name for NominalSpec listed in Project Setup --> Plant 3D Class Definitions --> P3d Line Group?

[darrelldixon]

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@quentin.contreras wrote:

In Plant 3D a "Spec" refered as when you are routing pipe and adding pipe fittings or valves to a model, you start with a pipe spec.

A 3D piping model is spec-driven; it references piping components listed in a pipe spec. When you work with piping in a 3D model, the pipe spec provides the material, rating, and connection details.

Spec files are created using the Specs and Catalogs Editor. For more information about pipe specs, see Introduction to Specs and Catalogs.

In combination with the project joint settings, the pipe spec determines which fittings and fasteners are used when connecting and routing pipe. For example: it specifies the socket weld fittings for pipe under 3”. Each pipe segment and fitting in the model originates from a pipe spec, except for custom parts.

I am not clear where exactly you are refering to the nominal spec. Is this in reference for the Property Name for NominalSpec listed in Project Setup --> Plant 3D Class Definitions --> P3d Line Group?

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Yes. I am familiar with pipe specs and catalogs and we have placed pipe in our model with the appropriate spec. When looking at these items in the Data Manager, there is nothing listed under the field "nominal spec". I am curious as to why this is different.

The tag generated for a line group looks for "nominal spec" and I don't know how to assign it the "spec" that was already linked to the pipe in that line when it was initially placed.

[dave.wolfe · Accepted solution]

So, two key ideas to separate out in your mind, physical line properties and nominal properties.  A pipe line group represents nominal properties (nominal size/spec) because some of the segments may include other sizes or specs.

For example, a line group that connects from a 4" 300 lb nozzle on a tank to a 2" 150 nozzle on a pump may include a spec transition at the nozzle and will include a size transition at the pump.  So, the same line group has to be able to include the 2" size, 4" size and maybe even a 1" size for a drain.  However, in our reports, and isometrics, we would still refer to the line as a 4" size assuming that the majority of the piping is 4". The 4" size would be the nominal size.

The physical size (or the size stored on the parts themselves) of course will alway represent the actual size of the part.

[darrelldixon]

I understood the nominal size, but didn't know that also applied to a spec designation, but that makes sense now.

So, how do you define the nominal spec for a group? Is that something that is aquired, or are you able to enter that in data manager?

[dave.wolfe]

They are both defined in the P3D Line Group out of the box, and you can enter it in the data manager.

[Vitornis]

Where can you fill out the Nominal Spec Field? I would like to fill this out so that it will show up in my Iso title block?

[dave.wolfe]

Please create new posts for new questions. The reply above your comment contains the answer, the data manager.

http://www.pdoteam.com/2013/06/setting-service-and-other-line-group-properties/

[tsabinas]

It's been a few years since this question was asked, but since it's still one of the top items in a google search I am assuming a lot of people still have this question and wonder what use the Nominal Spec field is.

Pretty much the nominal spec field is useless, even in the P3D 2021 sample project Autocad does not use this field at all.  That means in both the P&IDs and the models the Nominal Spec is a manually entry field if you want to use it for something like ISOs.  Unless you go back to the beginning and you have to setup your project so you are doing the model from the P&IDs

In the P&ID setup, under Pipe Line Group you set your list of Nominal Specs (Specs names used in the project).  For example on a project I did, the spec names were ACA, BCA, DCA and ECA, so I modified the Nominal Spec list to match those names.

Then in Pipe Line Segments -->Spec, instead of that being a list, I set an Acquisition Rule to acquire the information from the PLG (Pipe Line Group) Nominal Spec.  And then I set the Pipe Line Segment field to Read Only because I don't want someone to over-write the acquisition.

Then, so I didn't have to go to the data manager every time to assign the Nominal Spec, under Pipe Line Segments Tag Format, I modified the tag format so instead of reading Pipe Line Segment-Spec, it reads PipeLineGroup-NominalSpec.

Out of the box, it is setup so the Pipe Line Group (P&ID) Nominal Spec is transferred to the P3D Line Group (Model) Nominal Spec.

For some reason though, in the Plant 3D DWG Settings--> piping and equipment--> spec field, autodesk does not allow you to set up that field to acquire the Nominal Spec field.  So I just go into P3D line Group and in the Line Number Tag format, I set up my Line number for Nominal Spec - Number - Service (all Acquired from P3D Line Group fields)

Lastly, I set my Pipe Line Segment Tag to read Target Object Size, P3D Line Group Number and that gives me the result of Size-NominalSpec-Number-Service.

By doing it that way, we only have to enter the Nominal Spec in one place and it is then used for our P&ID tags, Ortho tags and is a field that can be added to the ISO template.

Now, if the spec changes in the P&IDs then in the model you have to go to data manager and  manually change it for whatever line numbers are changed.  So in change management it is two manual changes (P&ID and Model).

After changing the nominal spec in the data manager you do have to run the PLANTREFRESHACQPROPERTY command to get the change to show in the Pipe Line Segment Tag.

I hope this helps anyone that is trying to increase the efficiency of getting a project out the door, or just anyone that has thought, what the ~!@#$ is that Nominal Spec field good for?

[Zhars]

Facing a similar issue when creating a line list report.  The out of the box Line List report available @ data manager uses the Line Group to group all of line segments.  However by default the Nominal Size/Spec are blank and not linked to anything.  I have selected an acquisition rule for Nominal Spec to pull the Spec from the Line Segment which works well.  However for the Nominal Size, the acquisition rule only works when the Line Segments have one size.  If there are multiple sizes (reducers etc.), the acquisition rule is not able to select the largest size from the Line Segment.  This is a bit of a pita.