Swing-Bolt Closure Top lug Material 1

[humbubble]

Is the top lugs of a Swing-Bolt Closure considered pressure bearing. One of our designs has the top lugs @ 3/4" thk SA-36. If they are considered pressure bearing they can only be up to 5/8" thk. The part I'm unclear about is the "pressure bearing" part. Can anyone clear this up?

 

[jamesl]

These lugs are definitely pressure parts, and subject to 5/8" thickness limit in UCS-6.

 

[TomBarsh]

I assume the swing bolts clamp the closure (bolted cover) to the mating flange, so these bolts are pressure parts. How is the load from the internal pressure transferred to the bolts? Through these lugs? If "yes" then the lugs are subjected to the load on the closure from internal pressure and the lugs are "pressure bearing parts".

 

[humbubble]

I understand that it is subject to the load, but is it what ASME considers "Pressure Bearing"? I believe it to be pressure bearing. For the pressure vessel to function and contain the pressure the assembly must meet code standards for pressure bearing part. What I'm looking for is a clear-cut answer, preferably something that can be pointed out in the code book.

 

[jamesl]

The lugs are doing the same thing as the portion of flange that has bolt holes.

 

[jamesl]

How about UG-4(a):

"Material subject to stress due to pressure shall conform
to one of the specifications given in Section II, Part
D, Subpart 1, Tables 1A, 1B, and 3, including all applicable
notes in the tables, and shall be limited to those that are
permitted in the applicable Part of Subsection C."

The lug material is subject to stress due to pressure.