When you add an MvPart to a drawing, no systems are assigned to its connectors. If you connect a pipe run to an MvPart connector, the connector inherits the system setting from the connecting pipe object.
You can specify the system for MvPart connectors. Then, if you use the add grip to begin drawing pipe runs directly from the MvPart, the system is already specified for the new run.
If you change the system for an MvPart connector that is connected to a pipe run, the system for the pipe run changes to match that of the MvPart connector.
To change the system assigned to an MvPart connector