API650 Figure 5.7b 'neck bevel should be about 10 degree'

[mechengineer]

'neck bevel should be 10 degree' as per API650 Figure 5.7b. Does it is mandatory?
It will be labour cost to make the bevel on the nozzle neck (unnecessary). I persoanllt think it is unecessary, even if for pressure veseel, thre is no such requirement (ASME VIII-1).
Thanks.

 

[JStephen]

If you make it 11 degrees, the tank will fall down.

 

[HTURKAK]

[quote='neck bevel should be 10 degree' as per API650 Figure 5.7b. Does it is mandatory?][/quote]

It is not mandatory requirement for Shell Manholes and Nozzles Details ( for Figure 5-7B )
But it is mandatory requirement for Flush-Type Cleanout Fittings see fig. Figure 5-12.

The use of ' shall and should ' in standard,

Shall: As used in a standard, “shall” denotes a minimum requirement in order to conform to
the specification.
Should: As used in a standard, “should” denotes a recommendation or that which is advised
but not required in order to conform to the specification.

 

[mechengineer]

Thanks, Hturkak.
But I think that is not good recommendation to grind the 10 degree.It will waste cost and man hour for the unnecessary work.