Loop Placement and Nesting

Placement

User-defined loops are given priority over calculated loops.

Placement	Description
Placement of User Defined Loops	Except for a few situations, user-defined loops are always placed at the location and with the user specified orientation and height. If, for some reason, the location, orientation, or height are not feasible, then AutoRouter generates an error. There are a few conditions that are not allowed and will always produce an error: When located at the intersection of two pipeways. When located at the location of another user loop with an opposite orientation. When located at the location of another user loop with a different loop height. When the loop is flat and intersects adjacent lines on the pipeway level. When the loop minimum width cannot be satisfied because of already existing user loops at that location.
Placement of Calculated Loops	Calculated expansion loops are placed after user-defined loops. Ideally, the location of the loop is based on dividing line expansion equally among the loops. When feasible, loops are located within two bay lengths of the ideal location; otherwise, generates an error. Preference is given to locations nearest the ideal location that also allows maximum nesting of neighboring loops. There are a few conditions that are not allowed and will always produce an error: When there are too many loops at the required location to satisfy minimum width requirements. When there are user loops with incompatible loop orientations or heights that do not permit the calculated loop placement at the required location. When there are pipeway obstructions that do not permit calculated loop placement at the required location (for example, other pipelines, other loops, or obstacles).

Placement

Description

Placement of User Defined Loops

Except for a few situations, user-defined loops are always placed at the location and with the user specified orientation and height. If, for some reason, the location, orientation, or height are not feasible, then AutoRouter generates an error.

There are a few conditions that are not allowed and will always produce an error:

When located at the intersection of two pipeways.
When located at the location of another user loop with an opposite orientation.
When located at the location of another user loop with a different loop height.
When the loop is flat and intersects adjacent lines on the pipeway level.
When the loop minimum width cannot be satisfied because of already existing user loops at that location.

Placement of Calculated Loops

Calculated expansion loops are placed after user-defined loops.

Ideally, the location of the loop is based on dividing line expansion equally among the loops. When feasible, loops are located within two bay lengths of the ideal location; otherwise, generates an error. Preference is given to locations nearest the ideal location that also allows maximum nesting of neighboring loops.

There are a few conditions that are not allowed and will always produce an error:

When there are too many loops at the required location to satisfy minimum width requirements.
When there are user loops with incompatible loop orientations or heights that do not permit the calculated loop placement at the required location.
When there are pipeway obstructions that do not permit calculated loop placement at the required location (for example, other pipelines, other loops, or obstacles).

Nesting

Width and length of user-defined and calculated loops are treated as minimum values so that the loops can be nested over the required number of bays and bents from the common loop center.

The project’s Minimum Line Spacing parameter is used to insure a minimum distance between:

Pipe supports to the first elbow weld along the outermost loop width and innermost loop length.
Pipe supports to outer insulated line diameter along the innermost loop width.

Pipelines are berthed in a loop by diameter. To maximize loop dimensions, large diameter pipes are berthed on the outside of the loop.

Loop pipes of a diameter equal to or larger than the 45 Inline Elbow Threshold (as set in the project set-up) rise above the pipeline via a 45 degree inline elbow connection.