I have a situation with steam jacketed pipe. We have jump-overs for the steam from one jacket to another; for example at a valve. The jump-over is 3/4 inch and connects onto the jacket with a 3/4 inch half coupling. Unfortunately, the half coupling is installed directly onto a circumferential weld of the jacket piping. Steam in the jacket is at 50 psig at close to saturated temperature. I am aware that ASME Section VIII Division 1 does not prohibit this configuration (UG36 and UW14) but I cannot find any reference in either B31.1 or B31.3 that mentions anything about such a configuration on piping. I would like the forum's opinion on this arrangement. I realize that I can change the location of the jump-overs but I would raather not do this if this configuration is an acceptable construct.