Branch Rule

Overview

This section provides a brief overview of the Branch Rule tables.

The Branch Rule ensure that when you create a branch, the connection type is compatible with the shape dimension of the header and the branch.

In Data Setup, this definition table should be assigned to:

when using file-based tables, the Branch Rule item in the resource table of HVAC Design Resources.
when using Engineering Specification objects, a specification in the resource table of HVAC Specification Resources.

Table Description

This section describes the customization options of the Branch Rule tables.

The following table describes the meaning of each column.


Parameter	Type	Importance	Input / Output	Description
Header Equivalent Diameter	Nominal Size	Required	Input	Used for filtering.
Header Shape
Material
Material Category
Branch Equivalent Diameter	Nominal Size	Required	Input	Used for filtering.
Branch Shape
Branch Material
Branch Material Category
Branch Case	String	Required	Output	The method of attaching the branch to the header: STUB-IN, STUB-ON, OnSurfaceCompo or InHeaderCompo.
Part Subtype	String	Only required when BranchCase = OnSurfaceCompo or InHeaderCompo	Output	The type of part you want place.
Branch Angle	Angle	Optional	Output	The angle between the branch and the header.
Branch Point Offset	Length	Not required when BranchCase = InHeaderCompo	Output	The distance between the axis of the header and the branch point.
Branch Port End Style	String	Not required when BranchCase = InHeaderCompo	Output	The style of the branch port: WELD STUB IN, WELD STUB ON or WELD SET ON.
Branch Port Height	Length	Not required when BranchCase = InHeaderCompo	Output	The height of the branch port.
Branch Port Width	Length	Not required when BranchCase = InHeaderCompo	Output	The width of the branch port.

File-Based Table

A typical Branch Rule file-based table is shown below:


V_EquivalentDiameter	BranchEquivalentDiameter	BranchCase	V_SubPartType	BranchAngle	BranchPointOffset	BranchPortEndStyle	BranchPortHeight	BranchPortWidth

Important: The columns must all be found in this order to be correctly read by the app.

Engineering Specification Table

A typical HVAC Branch Rule Engineering Specification table is shown below:


Header Equivalent Diameter	Header Shape	Material	Material Category	Branch Equivalent Diameter	Branch Shape	Branch Material	Branch Material category	Branch Case	Physical Part Subtype	Branch Angle	Branch Point Offset	Branch Port End Style	Branch Port Height	Branch Port Width

The columns definitions are as follow:


Column Name	Column Type	Link to Table	Link to Column
Header Equivalent Diameter	String	Duct Reference Dimension	Equivalent Diameter
Header Shape	String	Duct Reference Dimension	Shape
Material	DS Material	Duct Reference Dimension	Material
Material Category	String	Duct Reference Dimension	Material category
Branch Equivalent Diameter	String	Equivalent Diameter	Equivalent Diameter
Branch Shape	String	Equivalent Diameter	Shape
Branch Material	DS Material	Material	Material
Branch Material Category	String	Material	Material category
Branch Case	String	-	-
Physical Part Subtype	String	Part Subtype	Physical Part Subtype
Branch Angle	Angle	-	-
Branch Point Offset	Length	-	-
Branch Port End Style	String	End Style	End Style
Branch Port Height	Length	Duct Reference Dimension	Height
Branch Port Width	Length	Duct Reference Dimension	Width

The table has the following attributes:

Standard
Max temperature
Min temperature
Fluid
Fluid Category

Note: Values in the table must respect some rules. For more information, see Shape of Rigid Duct.

Branch Port Technology

The available technologies are STUB-IN, STUB-ON, SET-ON and OnSurfaceCompo. If the offset value is unset, the value is automatically calculated according to the following rules: