Explains the Size Supply Plumbing Line dialog box.
The Design Values section of the Size Supply Plumbing Line dialog lets you define the design parameter values of the supply run. Before you enter values, you need to know the source of the water and the pounds per square inch of pressure being produced. You also need to know the pressure requirement for the fixture located at the highest elevation in the building model.
Design Values section of the Size Supply Plumbing Line dialog box
Plumbing Line Sizing Table
The plumbing module reads the values of the valves and fittings in your drawing and verifies that they are correct for the length of supply line in the run.
- Select the supply plumbing line sizing table (pipe sizing table) that you created based on applicable codes, such as the Uniform Plumbing Code.
- To verify the values in the table definition, open it by clicking the Plumbing Line Sizing Table icon.
- Click the Equivalent Plumbing Line Lengths tab.
Restrict Velocity
Selecting Restrict Velocity prevents a plumbing line size with a flow velocity that exceeds the value that you enter. The restricted velocity should be the maximum velocity that you want in the run. This can avoid issues such as water hammer. The default restrict velocity value is 10 ft./s.
Pressure at Source
Pressure at Source defines the amount of water pressure coming into the building. For example, the pressure at the source of the building could be from a booster pump. The default value is 60 psi.
Pressure at Highest Fixture
Pressure-Highest Fixture defines the minimum amount of pressure to be supplied to the highest-level fixture in the supply run to ensure adequate flow. For example, a third-floor toilet fixture at an elevation of 35 feet might require 15 psi in order to flush. The default value is 15 psi.
Friction Loss-Water Meter
If a water meter is included in your design, then you should account for the total friction loss of the water meter. A water meter is considered part of the water utility. Typically it is not a part of the building. Often it is not included in the design. Therefore, the default value is 0 psi.
Hazen-Williams C-factor
The C-factor determines the friction loss of the run using the Hazen-Williams formula. The factor “C” is known as the “Hazen-Williams C” or “friction loss coefficient C.” The C-factor relates the relative roughness of the interior wall of the pipe and varies between different types of pipe. The C-factor is typically 100 for steel pipe and 130 for brass and copper. The default value used in sizing supply plumbing lines is 100.