Questions for structural steel fabricators building miscellaneous steel:

What is the commonly seen weld for doglegs on the common channel stringers used for miscellaneous steel stairs in buildings? 

Do you commonly see CJP welds?

Or PJP welds? 

Do you UT the splice?

AISC and AWS D1.1 would be governing codes.

The co. i weld for have us cjp on all splices and doglegs for stair-stringers, and we ut all cjp welds. All are prints come from a third party,so I don't know if this is a company guideline or customers either way i get paid the same low low low.

We inspect lots of C doglegs, usually CP, and UT if over 5/16" web.  (California)

As a structural engineer, I typically specify PJP's because we don't (generally) need the full strength of a CJP in the dogleg portions of the stringers.  This is usually not the highest stressed part of a stair stringer so if the calcs work with a PJP, that's what gets called out.  I am careful to specify the effective throat required and we typically specify special (full-time) inspection so that is our quality control.  Testing is visual unless something is suspect, then we have made small cuts or borings to verify effective throat and penetration.  We specify welding on both sides of the joint but don't grind unless the stairs are architectural.  I like to leave joint prep up to the fabricator.  And we always get the WPS's for these welds (for all welds, actually) and weldors certs.  This is in California also.

Strictly speaking, in AISC, stairs are considered miscellaneous metals and are not covered by the AISC Code of Standard Practice.  You have to cover them in a miscellaneous metals specification.  Frequently, we just specify that stairs shall be considered structural steel and subject to the Code of Standard Practice so all steel is covered in one place.

Bob G.