Replacement Fitting Sketch: Prevent a Second Mirrored or Rotated Remake

Fast answer

Sketch the replacement from a named viewing direction and mark airflow, top, upstream, downstream, connector types, control points, and fitting movement. Make it impossible to read the sketch from the opposite side.

What to check

1. Write “looking upstream” or “looking downstream” on the sketch.
2. Mark top and the building direction or grid reference.
3. Show which side rises, drops, shifts, or stays flat.
4. Include end sizes, connector types, verified dimensions, piece mark, and revision.

Do not

Do not rely on a photo alone or use left and right without stating the viewing direction.

Ask the foreman

“I redrew the remake looking downstream, marked top and grid north, and showed the offset moving left. Can you verify the orientation before the shop releases it?”

Why it matters

Most second remakes happen because the dimensions were corrected but the viewing direction remained ambiguous.