I would be starting with the welding of 4130 material with ER100S-G(TIG,MIG), E101T1-GM(FCAW) and F9P8-EF3-F3-H4(SAW). PWHT @ 1150 F for 2 hours. 3 Sizes of pipe
3" Sch 160, 9.61 O.D. X 1.25" and 18" O.D. 1.88 AW. I have been reading a lot about this material. But some practical experiences on 4130 will help me in taking care while welding the PQR.
Request everyone's opinion on this.