Draw Process Links

This procedure is used to draw process links between instrument items and process items, for example, a connection between a pressure indicator and a pipe or equipment item. Such links do not receive a line number.

If Instrument Process Links, also known as "Legacy" Process Links, are to be used (the PLK item type), for example, Process Links without the functionality introduced with AVEVA P&ID 7.2 SP3, a number of factors should be considered when drawing process links if data is to be exported to an XML file in the ISO 15926 schema format. For details.

Note: If required, main pipes can be drawn using the Process Links pipe style. Pipes drawn using this method will look like Process Links but will functionally be Pipes.

Associated Project Configuration Options

• The default style for Process Links is selected from the Default Process Link Style list in the Pipes –Settings Sub-Category pane of the AVEVA P&ID Project Administration program.

• The default style for Instrument Process Links is selected from the Default Instrument Process Link Style list.

• The maximum and default process link sizes are selected from the Maximum Allowable Size for Process Links and Default Size for Process Links lists.

  Note: Process links will be drawn at the same size as the main pipe they are connected if no default size has been specified.
  If a default size has been set they will be drawn at this size, unless the main pipe they are connected to is smaller, in which case they will be set to that size instead.

• If only Instrument Process Links, also known as "Legacy" Process Links, are to be used, for example, Process Links without the functionality introduced with AVEVA P&ID 7.2 SP3, the Use Legacy Process Link checkbox in the Pipes – Settings Sub-Category must be checked.

  Note: Non-"Legacy" Process Links are drawn using the pipe item type (PMA) in the process link pipe style. In other words they will technically be branches between main pipes and offline items. They will therefore have all the functionality of pipes and may be labelled and edited in the same way.

Example

Procedure

Draw Process Links

Note: Before starting, make sure that the Use Legacy Process Link checkbox in the Pipes – Settings Sub-Category of the AVEVA P&ID Project Administration program is unchecked, otherwise Instrument Process Links, also known as "Legacy" Process Links will be drawn.

1. Start the procedure by selecting the Process Link option in the Pipeline group of the Home tab.

2. The Command prompt will display:

   Indicate point for Process Link:

   Pick the start point for the Process Link.

3. The Command prompt will then display:

   Indicate point for Process Link:

   Pick the end point for the Process Link.

   Keep selecting start/end points for further Process Links, or press or select Enter to finish the command.

For process links drawn using the PMA (pipe) item type, the Label Pipes procedure will NOT start automatically even auto-labelling for pipes is on. The labelling procedure for such process links may be started manually if required.

Draw Instrument Process Links

Note: If the Use Legacy Process Link checkbox in the Pipes – Settings Sub-Category pane of the AVEVA P&ID Project Administration program is checked, the above procedure may also be used.

4. Start the procedure by selecting the Instrument Link option in the Pipeline group of the Home tab.

5. The Command prompt will display:

   Indicate point for Multilined Process Link:

   Pick the start point for the instrument process connection.

6. The Command prompt will then display:

   Indicate point for Multilined Process Link:

   Pick the end point for the instrument process connection.

   Keep selecting start/end points for further Process Links, or press or select Enter to finish the command.

Guidelines for Drawing Process Links

If "Legacy" Process Links are to be used (PLK item type), for example, Process Links without the functionality introduced with AVEVA P&ID 7.2 SP3, a number of factors should be considered when drawing process links if data is to be exported to an XML file in the ISO 15926 schema format.

Because of the limitations of the ISO 15926 schema not all arrangements of process links are supported, therefore the following guidelines must be followed to make sure an accurate layout of pipe networks is available for the 2D-3D comparison performed by the P&ID 3D Integrator.

Tees or any in-line components that split the flow should not be drawn with process links, e.g.:

In-line components that split the flow are:

• 3 way and 4 way fittings

• Valves and in-line equipment

• Port valves with more than two ports.

Instead, as in this example, the bypass should be drawn as branch of the main pipe, like so:

Process links should not be connected directly to equipment:

Ideally any tubing connected to a vessel should be a branch of a trim pipe, and at the very least they should start from a nozzle:

Process links should not be used as leader lines or to connect any items that are not meant to be part of a pipe network:

Signal lines or dummy lines should be used instead: