Before the
weld, check
the fit.
One pocket gauge. Two readings that matter before the first arc: internal misalignment and root gap.
A weld begins with the joint you give it.
Pipe ends can look aligned from outside while their inner edges sit at different heights. This Hi-Lo gauge reaches through the root opening to compare those inner surfaces. Its tapered leg also checks the root gap. Use the readings with the dimensions required by your drawing or procedure.
Two questions at the joint.
Internal misalignment
- Clean the pipe ends, root opening, and gauge contact surfaces.
- Loosen the screw and extend the two alignment legs.
- Pass the legs through the root opening; rotate the gauge 90° across the joint.
- Pull gently until both legs touch the inside surfaces. Keep the tool square.
- Lock the setting, rotate back, remove carefully, and read at the indicator line.
Keep both legs in contact with the inner surfaces. Tilting or uneven pressure can change the reading.
Root gap
- Clean the root opening and tapered measuring leg.
- Loosen the locking screw.
- Insert the taper until it just contacts both pipe edges.
- Keep the gauge square; do not force it into the opening.
- Lock the setting, remove without shifting the slide, and read at the indicator line.
The taper must touch both sides of the gap. Use light contact only.
Three moments to reach for it.
Before tack welding
Check the opening and internal alignment while the joint can still be adjusted.
At several clock positions
Repeat the check around accessible points of a pipe joint; one reading may miss a local mismatch.
Before the first pass
Record both values and compare them with the job’s specified fit-up limits.
Measure first.
Then make the call.
This inch-scale stainless-steel gauge covers internal misalignment from 0–5/32″ and root gap from 0–3/16″. It reports dimensions; the drawing, WPS, or inspection plan determines whether the joint is acceptable.
