High Temp Bolting

[JAV72]

I've been asked to check some connections for platforms being attached to a vessel. Connections are small brackets welded to a reinforcing pad on the vessel wall, platform arms are then bolted to the bracket. Seems straight forward enough but I have been given a design temperature of 500 degrees Fahrenheit. I have found information on reductions for the material properties of the plate components of the connections but have not been successful in finding high temperature effects on bolts. Any reference material recommendations?...perhaps something on the mechanical side, an ASME specification? Thanks

 

[EdStainless]

If you go to one of the bolting specs that have ASME coverage you can find the stress/temp tables in the Code.
Though unless the vessel gets a lot hotter than 500F the bolts won't be that hot (unless this is all insulated or some such thing).

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P.E. Metallurgy, consulting work welcomed

 

[JStephen]

For bolts normally used in ASME vessel work (ie, mainly flange bolts), see Table 3 of Section II part D of the ASME code.
Note that attachments outside the pressure boundary aren't actually governed by ASME, so you're not obligated to use those stresses.

 

[JAV72]

Ed/JS,

Thanks guys, that is the help I was looking for...have a good one.

 

[rb1957]

Is the point at that 500degF the bolt and the flanges may expand differently ?

How about thermal cycling ? (will the structure stay at 500degF for a while, or cycle (daily?) ?

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