We need to develop a welding procedure for welding L-80 Type 1 casing to cone shaped for lack of a better term "end caps" of 4130 material. the pipe and cones are 13.375" x 0.375". my greatest concern is the PWHT that would be required after welding. design temperature is -50F to +250F. design code is ASME B31.4. hydro test pressure will be 5500psi, operating pressure will be 2600psi. there will also be L-80 to L-80 welds on the piece will they also require PWHT? if anyone good give me some tips on this i would be greatly appreciative or if i more information is needed please let me know. thank you