Insulated main steam lines running from boiler stop valves to turbine main stop valves. The lines are 18 inches and 12 inches with 8 inch and 7.5 inch insulation thickness. The ambient temperature where this steam lines are installed is about 70F. Steam lines are warmed up during thecold start up, from 100F to 750F with a rate of 200F/hr.

The target of this FEA is to determine the thermal stresses caused ONLY by the temperature distribution in the pipe wall, which is determined from a transient heat transfer analysis. The temperature load is the only load applied in this thermal stress analys.

Attached snap shot shows the sections of the piping I am considering to analyse. I am thinking to use symmetry and slice the piping along its longitudinal axis. I will apply symmetry constraints to the cut out faces of the piping.

I am not sure what kind of constraints could I apply at locations labeled A, B as marked up on the attached snap shot.

I would appreciate any suggestions or advices regarding the type of constraints I needv to apply at thoe marked up locations.

Regards,

Bogdan