P & ID Drafting from India
P & ID Drafting from India - P&ID drafters are individuals who must care about every line, annotation and symbol on each piping and instrumentation (or process) drawing they produce. They should understand the need to learn to recognize when something does not look correct and to bring it to the attention of the proper source who can address the issue.
P&ID drafter is someone who is on their way to becoming a designer – as a high level P&ID specialist, a piping designer, or an instrument designer - through on the job training. This on the job training consists of constant research and interaction with process engineers, piping designers and instrument designers throughout the progress of each drawing. P&ID drafters must ask questions when anything is not absolutely clear or when something just doesn’t look right.
Tips for P & ID Drafting:
- Never draw P&IDs on a scaled border. Flow diagrams are not drawn to scale as they are graphic representations of flow and do not represent actual sizes of equipment or instrumentation.
- Rarely do two different designers mark up project drawings the same. Some leave out vital symbology while others show every detail. Do not simply draw what is shown on the mark-up.
If it is obvious that more should be shown, then show it. Provide the designer with the project’s Symbol and Legend sheet and ask them to follow those symbols when marking up the drawings. Be consistent. Always keep a copy of the project’s current Symbol and Legend sheet near for easy referral.
- Text style for P&IDs should be Simplex font.
- Newly minted drafters frequently make the mistake of thinking that speed is the quality which will be most appreciated by their new employers. Most are surprised to learn that the very people they are trying so hard to impress with their quick turnaround, would much prefer that they slow down a bit and concentrate more of their efforts on accuracy.
- Marked up drawings should always follow the same color code. If drawings are received which are not color coded correctly, provide the following list to the person who marked up the drawing.
- red - incorporate items (add)
- yellow – items marked as “correct” by designers
- green - delete items
- blue or black - comments to drafter or designers personal notes (do not add to drawing)
- orange - items addressed by drafting (pickups) – to check your own work.
When drafting, always check your work twice. As you make each change, use a thin orange line on the mark-up to show yourself that picked up the mark. Do not use heavy slashes. And don’t cheat by making all your marks at the end...do each mark individually. While back checking the print of the newly edited drawing, circle each change on the mark-up with a thin orange line. At the same time, use the orange line method for each change on the check print. Always use this method to self-check and you’ll rarely miss any marks.
AutoCAD commands work in-context to make P&ID drafting simpler:
- Valves rotate automatically to align with the pipeline break line.
- Line tags automatically align with the line segment.
- Crossing lines break according to the project settings.
- Direction-dependent components automatically place in the right direction.