Pipe Line/Fitting Data
This window is used to supply the physical characteristics of the pipe and/or fitting (length, elevation, roughness, etc). A fitting can be included in the pipe unit by supplying its K-Factor value. If a fitting is included, PRO/II assumes that the fitting follows the line in the direction of flow and that the fitting and the line have the same diameter. To place a fitting before the line, you must use two pipe units.
Usage
To display this window, push the Line/Fitting Data button from the Pipe Main Window.
Line/Fitting Diameter
The line diameter can be specified either in terms of inside diameter or by nominal line size in inches. If the inside diameter option is selected, supply the available pipe diameter in the data entry field. The maximum allowed diameter is 144 inches or its equivalent.
If you want to supply a nominal pipe size, select the desired size from the drop down list box. PRO/II provides a default pipe schedule number (for most cases it is 40) which is the most commonly used value. The diameter of any included fitting will be considered to be equal to the line diameter.
Note that the line diameter is necessary only for pressure drop calculations. For line sizing calculations, it is optional since a set of line sizes for the calculations will be provided in the Line Sizing Window.
Line Length
This entry specifies the desired pipe length. To simulate a fitting by itself, provide a negligible (or zero) line length. The maximum allowable length is 3,280,000 feet (about 621 miles) or its equivalent.
Elevation Change
This entry specifies the change is elevation from inlet to outlet. The default rise is zero (i.e. horizontal). The value may be positive (uphill) or negative (downhill), but cannot exceed the total length of the pipe provided in the Line Length field.
Fitting K-Factor
Supply the necessary k-factor value if you desire to include a fitting in the pipe unit. The k-factor is defined as the total resistance coefficient for the fitting, including allowances for multiple fittings, valves, and exit losses. This field is not available when line sizing calculation is selected.
Roughness
A roughness value can be supplied either in Absolute or Relative units. By default, PRO/II supplies an absolute roughness of 0.0018 inch. The roughness applies to the fitting as well as the line, when the pipe unit includes calculations for both.
Segments
This entry divides the total line length into a number of shorter, equal-length segments for pressure drop calculations. The default value is one segment. but it allows a maximum of 200. To override the default, click the highlighted text (the number) and enter the desired value.
Since pressure drop is calculated from the average properties of each segment, we recommend dividing long pipes into segments of 10,000 feet or less. The accuracy of the answer depends on the number of specified segments. If the unit fails to converge, PRO/II automatically increases the number of segments by a factor of five and tries to re-solve the unit.
Print Segment wise Data
Choose this option for printing the segment wise data results in the output report.
Most of the above parameters (except elevation, nominal pipe size, and segment) can be referenced using the Define system relative to any available unit operation or stream parameter calculated elsewhere in the simulation.
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