Over the last three releases of AutoCAD Civil 3D we’ve seen a major effort by Autodesk put into gravity Pipe Networks and Storm and Sanitary Analysis. That’s paid off in some pretty useful and productive tools. Autodesk put on the gloves for a new boxing match in the 2013 release.
Pipes Under Pressure
Pressure Pipe Networks and their companion Features are brand new for 2013. We now have Pressure Pipe Networks, Pressure Pipe Part Lists, Pressure Pipes, and two different types of “structures” – Fittings and Appurtenances. “Appurtenances” are all the other stuff like valves, regulators, etc. that may be part of pressure system aside from the connecting Fittings between the pipes.
One of the better things about Civil 3D is the consistent interface approach the software employs. If you’ve used Civil 3D Pipes in your work before, the basic concepts, creation, and editing processes of Pressure Pipes are much the same. Most of the new interface and the creation and maintenance of Parts Lists and all the attendant Styles should be relatively familiar ground for the experienced user.
However, in Pressure Pipe Networks (PPN) things are a bit different for both specific discipline reasons and because Autodesk took a somewhat different approach to some of the technical aspects of Pressure Pipe Networks as well. Simply put - more of what’s going on is driven by your current Pressure Pipe Part List and the backend data in the database driven Catalogs than in the existing gravity Pipes application.
AWWA Content
Autodesk says they’ll ship 3 (three) Imperial Pressure Pipe Catalogs (PPC) based on the American Water Work Association (AWWA) standards and one Metric PPC. The AWWA PPCs include three classes of connection systems – Push On, Flanged, and Mechanical. The initial Metric PPC will only include a Push On connection system.
The PPC are editable datasets. That is good news. The Catalogs are not, however, editable from inside the software. You must look for the separate really basic application to do that where Civil 3D is installed. The 2013 release of Civil 3D does include a command to build a complete Pressure Network Parts List from the “current” PPC.
The Pressure Pipe Design Interface
The Pressure Pipe Network design interface works primarily in Plan. You may reference either or both a reference Surface and/or Alignment. In the Ribbon interface a familiar “Cover” property locates the component’s elevation (at the XY pick points) based on the currently referenced Surface. You may construct Pipes alone or Pipes and Bends together. You may also optionally place Fittings and Appurtenances and connect them with Pipes after the fact. In my limited experience I ended up employing all three methods and was glad for the built in flexibility.
It’s a Bit Mind Bending
Pressure Pipes support both Straight and “Curved” pipes. The specifics of the allowed direction, Pipe deflection tolerance, and allowed Pipe curvature are driven by the current Fitting and Pipe data values from the Part List. Remember that these Part List property values came from a Catalog database when the Parts List was made.
Plan it That Way
In Plan Civil 3D generates an on screen “Compass” tool when you construct pipes. The plan Compass reflects angular possibilities from the Fitting choices available in the current Parts List. Therefore, if you’ve only included 90 and 45 degree bends in your Parts List the Compass reflects the fact. The Compass interface tool helps you visualize and “snap to” these “acceptable” directions.
The Civil 3D 2013 PPN interface also provides handy, new Dynamic glyphs as an aid when you must make a connection to an existing “structure” or break a Pipe.
The design interface initially takes some getting used to because of the “hidden” data driven constraint system operating behind the scenes. ACAD and Civil 3D transparent alignment commands (e.g. ‘SO) do work, but you can get unexpected results based on the available Parts in the “system”. While the Compass will display in 3D as shown below, the tool is NOT functional in the 3D viewport in this release.
Get a Grip on Pressure Pipes
The PPN parts have decent and intuitive grips to help you perform typical rearrangements. For example: you need to flip the direction that a tee or a bend is pointing. These new PPN grips even help with construction tasks like generating a new pipe segment from an existing part connection.
Choosing the specifics of Pipe size, Fitting, and Appurtenance are based on pull down menus generated from the Part List. If your design requires you change size, structure type, etc in mid-stream you do have to mind these interface pull-down selections carefully or go back and fix things later. Civil 3D does help you find the problems you may have created as we shall see later.
In the betas a specific Pressure Pipe Part List did not appear to be confined to a single type of connection system. That’s good at one level since a more complex Parts List does emulate the part selection issues we may face in many real world systems. This flexible and more capable approach does mean a user has to know and have some experience with the Parts List specifics. I just had to ask and consternate a bit about the "adaptive" fittings that have to go between the different "connection" systems.
Pressure Pipe Network Analysis
Once you have your PPN built, there are “analysis” Design Checks for Coverage and other Design Criteria technical "infractions" a user may create within the network. For example: you’ve exceeded the allowed pipe deflection angle for fitting (of type and size) that you placed and edited. The provided visual quality assurances feedback is basic and typical of Civil 3D. It is reasonably effective too.
There is no interference checking in Civil 3D 2013 nor are there the Interference Styles to display such conflicts. There are no formal pressure system engineering analysis tools in there either. This is round one after all.
You can manually create an Alignment Feature from selected PPN parts and the reference alignment will stay connected to the pressure system if you don’t manually edit the alignment itself. The link is one way. You can add selected PPN parts to a Profile, edit the properties of the parts from a Profile View, and annotate them there. The basic processes are consistent with the existing gravity Pipe Network interface.
Publish on Demand
You can produce reasonable annotated Plan and Profile plans of your Pressure Pipe Network with the tools and the associated Pressure Pipe Feature Styles. I constructed Filled, Double Line, and Single Line representations without undue effort. The Styles properties for the various new Features closely resemble existing Pipe Feature Styles.
Annotative Label Styles are a bit more problematic because of the number of potential values you have to get your head around and the dearth and/or wealth of information available to users in the Catalog data. The Pressure Pipe Parts List didn’t appear to currently expose in the interface everything that’s in the Catalogs to the user. Way too much information is often overwhelming, but sometimes you really do need to know the specifics without having to go elsewhere to find them.
In this initial release Pressure Pipe Networks you should not expect all the bells and whistles that have already evolved in gravity Pipes. There are only Plan, Profile, and Model representations for Pressure Pipe Networks. There is no display of the new Pressure Pipe Network Features in Section. That was annoying.
The beta Catalogs I had access to were limited in materials, sizes, annotative detail, and the number and types of Appurtenances in particular. Don’t expect all the site design functionality you probably want and may expect out of the box in this “round one” version of Pressure Pipes in Civil 3D. You can unquestionably do that kind work with it, but you’ll have more essential setup work to do beforehand.
When it’s all said and done, the new Pressure Pipes feature in AutoCAD Civil 3D 2013 still beats the heck out of tweaking a gravity Pipe Network to do the job of basic Pressure Pipe design poorly. Certainly, the necessary data essentials are there for some more in-depth pressure for even more BIM for Infrastructure in our future.