You use the following features to create a duct run:
The path of this feature describes a straight line. This feature is defined by two linear data points from a user. Basic geometric principles dictate that two points define a line, thus the straight section of a duct run is a straight feature, as shown in the following illustration.
This feature acts as a place holder for future connections to the run. It is located at the end of a run, where a port exists on a part that is managed by the run. When an end feature is connected to a run, it is removed and replaced with another feature, based on the nature of the addition to the run. An end feature represents either end of a physical duct run. When you change a cross section, the software automatically inserts a transition feature. Also, when you change routing direction, the software automatically inserts or changes the turn feature. You can type a value in the Angle box only if the specification is set for continuous angle type.
A transition feature represents a change in the cross section of the duct run. The path of this feature is defined by a transition between cross sections or sizes or other defining constraints that result in the first port of the part being fundamentally different from the second port. The result is a feature that must close the gap between these parts. The transition feature modifies the cross-section of a duct run. It allows you to change a duct to all possible combinations. Ducts use transitions to connect different segments of the duct run that have different dimensions or shapes. The default transition feature has cross sections that either you specify manually or the software defines by default. The feature type is concentric or centerline-aligned. The default values for these properties originate with the selected end feature or nozzle where you are inserting the transition.
The following illustration depicts the rule that defines the length of the default transition feature:
(A) - W2 or the value of the second width in the default transition feature
(B) - L or length in the default transition feature; to determine the length, subtract the second length from the first length; then divide the difference by the tangent of the transition wall angle; in algebraic form, the equation is L = (W1 -W2) / tan x (where x is equal to the transition wall angle)
(C) - W1 or the value of the first width in the default transition feature
This feature represents a deviation in a path resulting in a turn. Turn features, such as elbows, miter elbows, and gooseneck elbows, change direction of the duct. If the centerline of the active duct is not collinear with the existing duct, the software automatically inserts the turn feature at both duct ends. If the two ducts are collinear, the software merges the two sections into one section. The default turn feature has the same cross sections on both ends. An administrator can edit the reference data to add values to display as options in lists on the ribbon.
Properties for turning vanes and branch vanes in turn features and branch features appear on orthographic drawings but are not needed for the model. The property names are Number of Vanes and Vane Length, and you need to type the values for these properties. The vane material, vane thickness, and vane width are the same as the parent feature. If you modify a feature with vanes, the software automatically recalculates the vane length, part weight, and part center of gravity.
An example would be three data points provided by a user. The first two data points generate a straight feature. The third data point, if not in-line with the first set, constitutes a deviation in path from the existing straight projection, as shown in the following illustration.
(A) - Uses a width ratio (depth divided by width) to calculate the turn radius for a rectangle
(B) - Uses a width ratio (depth divided by width) to calculate the turn radius for a flat oval
This feature represents a break and a joint in the duct. It divides a duct along a straight section into two straight features to connect the ends of the two ducts at the cut location, such as butt welding, coupling, flange set, and joint sleeve. A split feature is specific in its design by representing a break and a joint in the ducting. Examples are a sleeve, weld, and a flange set, either sloped or flat. These examples also are called split parts, which the software reads from the reference data.
This feature represents junctions whose path is defined by branching components, such as tees, wyes and crosses. The location that you select can be on the duct surface for a square cross section or the centerline of the duct for a round cross section. When you locate the point on a duct surface, by default the software aligns it with the centerline of the duct. The third port of a branch feature will always, by rule, constitute a new run that is independent of the header connections. When you change routing direction, the software automatically changes the branch surface.
If you modify a feature with vanes, the software automatically recalculates the vane length, part weight, and part center of gravity. Properties for turning vanes and branch vanes in turn features and branch features appear on orthographic drawings but are not needed for the model. The property names are Number of Vanes and Vane Length, and you need to type the values for these properties. The vane material, vane thickness, and vane width are the same as the parent feature.
Along Leg Feature
This feature represents in-line components such as dampers or filters where port 1, the origin, and port 2 are collinear.
Moving a Leg
A leg is a set of continuously connected features routed in the same direction.
If you want to move a leg, select a straight feature, and then move it in the appropriate direction. The software adjusts the length of the selected straight feature to maintain the angle of the connected turns or branches.
If you move the leg by selecting all its features, the software adjusts the angle of connected turns or branches.
You cannot move a single turn this way.
If the leg move is constrained on one side, the move may result in a skew. Undo, and move the leg using a different selection.
What do you want to do?