Use this tab page to define the parameters of each of the element's connection ports. The number of connections on an object varies, of course, depending on the object: a Duct take-off has just one connection port, but a Duct Wye has three.
Use the pop-up to switch among the connections, and edit each of them separately. In this image, we have selected the “Branch” connection from the pop-up on Duct Wye’s Connections tab page.
Note that the 2D Symbol object preview on the Preview and Positioning panel gives you feedback (the triangle) on which connection you are editing: in this case, the Branch of the Duct Wye.
Wall Thickness: This is the thickness of the MEP element’s wall.
Connection Type: Choose a Connection Type as applicable. For example, a ductwork element’s connection can either be simple or flanged. If you choose Flanged, enter a value for its width in the field below.
MEP System: If the element is generally used with multiple MEP systems (e.g. heating/cooling), then the MEP System pop-up is found on the Connections tab page. Use it to assign an MEP System (defined at Options > Attributes > MEP Systems) to the currently selected connection. (In contrast, single-function elements - such as bends - are assigned a single MEP System attribute on their General Settings tab page.)