Civil 3D model pipe scale issue

[dkafel]

I've been learning this program and believe it's the best program to use for modeling future underground utilities on the project I'm on. I've been able to create new pipe sizes and materials and have been able to set inverts and rim elevations, but I realized that it's not modeling the diameter of the pipes correctly. I'm in the proper units and my lengths dimesion properly, but say if I select a 48" HDPE pipe to be drawn, when it's modeled I can measure the diameter and it says 4.25". So, it's converting almost every 12" to 1". A 4" iron pipe models as 3/8" diameter. I've played with multiple new files and units, but can't seem to get it to model at the true diameter. Even if I scale the drawing it does not scale the diameter, only length. Is there something simple I'm missing? Thanks for any help.

[EMS_0525]

Its drawing in engineering units. 1= 1 foot not 1" Do you want it to draw it in architectural units? so 1= 1 inch? See if you can add a scale factor in somewhere of 12. All the drawings i have ever seen that had site plan information 1=1 foot.

[dkafel]

No matter what units I'm set at it won't model the actual diameter. I need them to model as the actual diameter so I can bring into a master file in navisworks for clash detection and coordination. Does Civil just not model the actual size since it's more of an engineering tool?

I model with the default settings CAD has given to a 12" concrete pipe. In the pipe settings it's given 12" for it's outside dimension, but will not model to 12", it does 0.4000 in Decimal units, or 3/8" in Architectural. If I click on the pipe and look at the properties it still reads it as a 12" pipe.

[dkafel]

Sorry, I meant to say in my last reply that 4" Pipe will measure as 0.4000 (Decimal) or 3/8" (Architectural) and a 12" Pipe will measure as 1.3333 (Decimal) or 1-5/16" (Architectural). I don't understand why it's not modeling it to be actual size.

[EMS_0525]

Do you draw 12" concrete pipe 12"? 4" D.I. pipe is 4.8" O.D. which is 0.40 feet, 4" pvc is 4.5" O.D. which is 0.375'. Personally i do a lot of the mechanical piping for my company and draw everything the correct size, 8" d.i. pipe is not 8" its 9.05" (0.754166')

 

If you are saying the program is drawing 4" pipe at 0.40', that is correct. If you are wanting to see possible pipe interferences and coordination with other disciplines maybe you should draw a bit more accurately. Smaller diameter pipe its not that big of an issue, but when you get into the bigger diameter pipe its more important IMO. 54" D.I. is 57.56" OD.

 

Quick Google search reveals 12" RCP has a 2" wall thickness. So that would make the OD 1.33' (1'-4"). http://www.bmeg.net/rcp.html

[CyberAngel]

You might check the pipe style under both Plan and Profile tabs. There is an option to set Pipe Wall Sizes. Sounds like you may have it set to absolute units.

 

Are the structures also drawn in architectural units, or is it only the pipes?