For a stub-in branch, the fitter marks and cuts the branch end into a curved saddle that follows the header's outside diameter, then bevels it for welding. The cut looks like an open fish's mouth. It is also a verb: to fishmouth a pipe. Fitters lay it out with a wraparound and template, a torch and a grinder, or a dedicated saddle-cutting machine.
Heard on the job
Fishmouth that 2 inch for the stub-in and keep your bevel even all the way around or it'll be a nightmare to weld.
Also heard as
- fish mouth
- saddle cut
- fishmouthing
Related terms
Olet
A forged branch fitting welded onto a run pipe to make an outlet without cutting in a tee.
Tee
A T-shaped fitting that splits or joins flow, with a straight run and a side branch.
Butt weld
An end connection where a beveled valve or fitting end is welded straight to beveled pipe with full penetration.