Hardware in Carbon Steel, Section VIII, Div.1 Vessel

[pperlich]

Good Morning Ladies and Gentlemen,

In UCS-11(c) the code states that Heavy hex Nuts shall be used...
I am yet to find a place in the code that says that heavy hex bolts are required.
Does anyone know why the code would allow using regular hex head bolts, but require heavy hex nuts?

Thanks, pperlich

 

[TomBarsh]

It seems that some of the common bolt specifications for use with Section VIII impose heavy hex head dimensions. For example, see SA-193 paragraph 13.3 with reference to ANSI B18.2.1 and "heavy hex", although there is allowance for standard heads to be used if specified in purchase order.

 

[pperlich]

It is true that many of the bolt specs are for heavy hex bolts, but not all of them.