Selection issues for horizontal container saddles
Thread Content
For the existing horizontal equipment (as shown in the figure), the operating temperature is 400°C. The casing is made of Q345R material. According to NB/T47065.1-2018, the design temperature for the saddle made of Q345R is -40 to 200°C. In this case, what material should be used for the saddle, or what type of support structure should be employed?
It is recommended to specify the saddle standard as “refer to NB/T47065.1” or use Q345R. Q345R can be used for pressure-bearing shells, and since the diameter of the equipment is not large, why can’t Q345R be used for the saddles? Of course, it is necessary to examine the stress conditions in various parts of the saddle. During installation, the saddle also needs to be insulated to reduce thermal stress differences.
That’s the thing; the software doesn’t perform the calculation: lol
Choosing Q345R was a poor decision; we encountered a superheated steam vessel operating at 450°C, and in less than nine years the surface showed severe blackening (after removing the insulation, most of the vessel’s surface was black; however, testing after grinding revealed that the thickness was still within acceptable limits).
Thank you to the original poster for the selfless sharing
I think I’ll try it this way: 1. Enter the data manually, as well as the allowable stress (I tried it, and it works). 2. Simply change the design temperature of the saddle to 200; this will depend on the insulation conditions. Or add a thermal insulation block in between, and then select in the software that the saddle should not be welded to the cylinder. (Haven’t tried it)