Jouko... another old guy by the name of Ron Haupt (Not as old as John Breen mind you) once stated "Trunions" do not belong on steam systems in power plants.....

My own opinion is that once you go into the creep range I try to minimize welded load bearing attachments as much as possible.... and I take into account the creep weld joint strength reduction factor as found in B31.3-2004. It will derate the strength of the weldment significantly above 950F.

B31 main has an ad hoc committee putting together common wording to be put into both B31.1 and B31.3 books concerning "W" B31.1 has in their own "wisdom" been unable to agree on what to do concerning "W" despite the fact the failure of a weld seam that killed 10 people that stimulated research in the creep weld strength reduction problem occurred in power plant!

Committees require consensus and sometimes one or two people with strongly dissenting opinion's make things difficult.