A rolling offset was guessed and the pipe points crooked
Treat a rolling offset as two moves happening at once. Find the true compound offset first, then use the 45° travel multiplier if you are using 45° fittings.
Do not guess a rolling offset by eyeballing two elbows until the pipe looks close.
Check
Measure side shift and vertical drop separately.
Use the Pythagorean method to find the true compound offset.
Apply the correct fitting-angle multiplier after the true offset is known.
Rotate adjustable elbows evenly so the end points line up square.
Verify downstream centerline before fastening the joints.
Steps
Measure side shift and vertical drop separately.
Use the Pythagorean method to find the true compound offset.
Apply the correct fitting-angle multiplier after the true offset is known.
Rotate adjustable elbows evenly so the end points line up square.
Verify downstream centerline before fastening the joints.
Say this to your foreman
This is a rolling offset at [location]. I measured [side shift] and [drop], found the true compound offset, and laid out the travel piece. Can you confirm the path before I lock the elbows?