Custom pipe assemblies can be represented one of two ways in the Family Editor. First they can be represented by using sweeps to represent the p-trap, wye, and associated piping, which creates a smaller file size and will reduce the size of the overall plumbing model but is not as accurate for quantity takeoffs. Refer to Figure 15.8.

Figure 15.8. Representation of a pipe assembly created with sweeps

The second is assembling nested families, which can allow for better quantity takeoffs for all the fittings, can create more accurate dimensional information when supplied by manufacturers, and can be easier for the plumbing designer to create. The downside is that it will produce a larger family file. The second option will help you achieve more of the building information modeling status while helping to increase productivity. Refer to Figure 15.9.

Now let's examine how nested piping assemblies are put together and some key areas to be mindful of:

Now that you have reviewed some of the items that make up a pipe assembly, you can place the pipe assembly family in your plumbing model and align it with the architectural plumbing fixtures without having to turn them off. If the architect adds a plumbing fixture, you now have the capability to visibly see the added fixture. By following this workflow, you can have the intelligent plumbing fixture on the architectural model and still tag and schedule through the architectural link.

Now let's take it a step further. If the plumbing fixtures that the architects are using match the same orientation of your pipe assemblies, you can copy/monitor the pipe assemblies directly behind the plumbing fixtures. Now when your architect moves a plumbing fixture, you will receive a warning that you need to coordinate your view. You will also have the capability to copy and change all of the plumbing fixtures on multiple levels all at one time. This can be a huge time-saver.

To use copy/monitoring, do the following:

If you highlight the assembly, you should see the monitoring symbol on the assembly. Refer to Figure 15.16.

Figure 15.16. Monitoring symbol shown on the assembly

To fully take advantage of copy/monitoring, you will need to coordinate all of your plumbing fixtures with your pipe assemblies, but you will find it is time well spent.

To modify and create new system pipes, go to the Project Browser, and select Families

Figure 15.17. Renaming pipe types

Now that you have your pipe types created, you will want to change some of the parameter options. First right-click the pipe you want to edit, and select Properties. This will open the Pipe Type parameters. Under Mechanical, you will find Material, Connect Type, and Class parameters. Change these settings to the appropriate types (refer to Figure 15.18).

Figure 15.18. Mechanical parameters

Under the Identity Data parameter group, the following parameters are available: Keynote, Model, Manufacturer, Type Comments, URL, Description, Assembly Description, Assembly Code, Type Mark, and Cost.

If you have a certain manufacturer, model, or other special note that you may want to denote on the plans, you can use these settings to further describe your pipe type (refer Figure 15.19).

Under the Fitting parameters, you'll find Elbow, Preferred Junction Type, Tee, Tap, Cross, Transition, Union, and Flange. Before you can adjust the rest of your system pipe type parameters, you need to create the fittings that go with your system pipe types. To accomplish this, you must go to the Project Browser and select Families

Figure 15.19. Identity Data parameters

Figure 15.20. Duplicating and renaming fittings to match pipe types

Once you have all your pipe fittings, go to the Mechanical parameters to find the Material, Connect Type, and Class parameters. Change these settings to the appropriate types. Also, you may need to modify the Loss Method parameter to K Coefficient From Table. Also verify that the table is set to the appropriate setting (refer to Figure 15.21).

Figure 15.21. K Coefficient From Table setting

Once the pipe fittings have been created, go back to the Pipe type parameters, and under Pipe Fitting, select the proper pipe fitting for your pipe type. Doing this will allow you to be able to filter and schedule piping for quantity takeoff purposes to achieve more accurate pricing (refer to Figure 15.22).

Figure 15.22. Selecting the proper pipe fittings for pipe types

To get to the Pipe material settings, select Home

Figure 15.23. Duplicating and renaming pipe material

If you want to adjust the sizing table, select Home

Figure 15.24. Pipe sizing

You can add to the fluids table by selecting Home

Figure 15.25. Fluids table settings

We hope you have everything set up in your pipe types to begin routing piping. The smaller a system, the more beneficial the autoroute feature. If you have a large system you are designing, then manual routing will benefit you more because of the nature of designs changing more often. To start, open Chapter 15 plumbing.rvt and Chapter 15 base.rvt found on www.wiley.com/go/masteringrevitmep2011. Next do the following:

You have four options to select for generating the layout: Network, Perimeter, Intersections, and Custom, and each one has several routing solutions to choose from that consists of a main (blue) and branches (green):

Figure 15.26. Generating layouts from systems

Selecting Fixtures When Autorouting

When using the autorouting feature, the number-one mistake that everyone makes is to try to select every fixture at one time, this will always lead to failure. The process is to use the Add And Remove From System ribbon of the General Layout ribbons.

Manual routing of piping is the next method. The advantage of using this option is that the designer has total control over workflow. When routing manually, start your piping out at the elevation that you know will be most likely out of the way of other disciplines. Cutting sections when routing piping can really improve the success of your coordination of your Revit model. Normally we will route our mains first so we can make sure that most of the piping will fit before connecting all the branches to the mains. To route piping, select Home

Before repeating this process for all of your plumbing systems, take some time to review the structural, mechanical, and architectural models. This can really cut down on modeling time. After coordinating the pipework and verifying the design flow rates, the layout is complete.

Whether you created your plumbing piping layout with autorouting or manual routing, you need to see whether your piping is reading flow. By using the Pipe Inspector, you can verify if your piping is well connected. To use this tool, click a piece of pipe that has been routed in a complete system. Once the pipe is selected, you will see the Modify Pipes ribbon. From this, select the System Inspector. With the System Inspector selected, pick any section of the pipe, and you will notice the GPM of the system and a direction of flow (refer to Figure 15.27).

Now you are assured your piping is well connected.

A lot of people think sloped pipe applies only to sanitary sewer. But in most specifications, almost all piping calls for a slight slope to be in the pipe so if systems are drained down, they are less likely to trap water. Vent piping has a slope because it is open to the atmosphere because of the vent having to penetrate the roof. Storm sewer is one of the most critical systems to make sure you have the proper slope because large rain water loads have been known to make roofs collapse. Now that we have you thinking about checking your specifications to see whether you need to slope more piping than just your drainage, let's look at how you will slope your pipe.

Figure 15.27. Verifying GPM and flow with the System Inspector

First you select the method of how you are going to run your piping using either the autorouting or the manual routing feature. When we lay out sanitary sewer, we always like to manually route our main first to establish where the sanitary is going to be leaving the building and make sure it has been coordinated with the civil engineer.

For sloping pipe to work properly, it needs to have a starting point and an ending point. To set up sloping pipe, open Chapter 15 plumbing.rvt and Chapter 15 base.rvt. Also download sanitary point of connection.rfa and wall cleanout.rfa. All of these files are found on www.wiley.com/go/masteringrevitmep2011. Next do the following:

If you need to track the slope, use an elevation tag. This will allow you to find the invert of the pipe along any point of the pipe. It can be used only in elevations, sections, and 3D views. It does not account for insulation of pipe.

Understanding pipe fitting controls can really make life easier if you are routing a lot of piping. There are several fittings that have this ability. When you are laying out your piping, turn 90 degrees to create a elbow. If you click the elbow, you will notice a plus (+) sign. If you click that sign, it will change from an elbow to a tee, allowing you to add more piping and continue your pipe routing. If you select the minus (−) sign, it will downgrade the fitting. When you see the

When you need to add valves to your piping, select the Home tab, and click Pipe Accessories. Use the Type Selector to select the type of valve you want to use. Most valves are based on "break into" type parameter, so you can place them into the pipe type, and they will break into the piping and connect (refer to Figure 15.30).

Figure 15.30. Fitting breaks into piping system

Real World Sceario: A Fitting End

In early 2008, an AEC firm in Knoxville, Tennessee, was working on a hotel project in Pigeon Forge, Tennessee. This 90-room hotel had already gone over the estimated projected design hours because of constant changes of field conditions, and it was the first hotel produced in Revit for this firm.

The building was a conventional plumbing sanitary with traditional multiple vent stacks. The project went out for bid, and when the bids came back, the building was slightly over the estimated budget, and the design team was asked to figure a way to get the cost back into budget. After carefully reviewing the project, the plumbing designer and engineer had decided to use a PVC version of a So-Vent plumbing system; only two families would have to be created for Revit: an Aerator and a De-aerator fitting. The cast-iron version of the system has been used in northern parts of the United States in high-rise design for years successfully.

The problem faced with using a system like this was that no one had installed such a system in East Tennessee. Plumbing code officials had not seen the system installed, and they stated it did not meet traditional methods of vent design. By using a section under codes that allowed the use of engineered plumbing systems, the design team proceeded to design the system. Because the existing layout was already in Revit, it was the logical choice to redesign the system in it.

Within two working days, the model and contract documents were revised with the new layout and then rebid. One-third of the vent system was reduced, which led to fewer holes being cut, fewer manhours, and fewer fire stopping costs. Since the plumbing contractor had never installed a So-Vent system before, being able to use printouts of the 3D model helped speed up the installation of the system and assure it was installed properly.

Although the project may have lost money for the firm, the hotel owner was happy with knowing that his construction costs were within budget and that his hotel could open on time.