Piping > Setting Up Fittings > Fitting Library Files > Fitting Library Creation > Stem Axis Direction
Stem Axis Direction
The stem axis of a fitting is an imaginary axis that is parallel to the y-axis of the inlet port.
It is applicable only to certain fittings and it represents the following:
The branch direction of a junction fitting along the positive stem axis.
The hand wheel direction of a valve along the positive stem axis.
The eccentric offset direction of a reducer along the positive or negative stem axis.
The reference axis for bolt hole straddling of a flange (straddling is done with reference to the positive stem axis).
For fittings involving the above graphical details, you must create the appropriate geometry either with reference to or along the stem axis directions specified, to achieve a consistent default orientation during fitting insertion.
Example: Stem Axis Direction
In the above figure, axis A_3 of the cone is created along the positive stem axis direction of the fitting, parallel to the inlet port y-axis of PORT0 (the inlet port that has the SIZE parameter). The fitting insertion functionality aligns the inlet port z-axis with the pipe segment and automatically orients the inlet port y-axis to its default direction, based on the orientation rules defined in the fitting insertion functionality. The default direction of the fitting is the fitting stem, since it is created parallel to the inlet port. During fitting insertion you can further rotate the stem about the pipe segment using the Rotation Angle option.