Isometric annotations: north arrow, slope, offsets, dimensions
Annotations tell you how the line sits in the plant: which way is north, which way the fluid flows, how far each leg runs, where it slopes, where it leaves the plane, and where it continues on the next sheet.
SymbolIsometricWhat it is
Rolling offsetA hatched triangle shows a leg that runs off the three main isometric directions, such as a 45 degree offset.
Item numberA number in a circle or box, with a leader to a fitting, points to the bill of materials on the same sheet, where the size, rating, schedule and material are listed.
ContinuationWhere the line runs onto another sheet or another line, a note gives the drawing it continues on, so a line can be followed from end to end.
Pipe supportSupports hold the line and control how it moves: resting supports, guides, anchors, hangers and springs.
Annotations
The north arrow is the first thing to read: it fixes the three isometric directions to the plant. Hatched triangles show legs that run off the three main axes, and every dimension is written, because an isometric is not drawn to scale.
Frequently asked questions
Which annotations appear on a piping isometric?
This legend covers north arrow, flow arrow, slope, rolling offset, dimension, item number, continuation, pipe support. Project legends may add more.
Can I download these symbols?
Yes. Each symbol page has free SVG files, and the hub has printable PDF charts.
From the isometric to the signed test pack.Deskely Testpack builds test packs from the line list and the drawings, records the test in the field and tracks reinstatement to the last spade.
- In production since 2014
- Thousands of daily users
- On MODEC FPSO projects since 2016