Openings in torisperical head 1

[Thruxton500]

Torispherical head, tensile strength exeeding 70000 PSI.
Is it OK to use max. stress values as given in tables referenced in UG-23 when nozzle is located in the spherical
Part of head

 

[gr2vessels]

Refer to ASME VIII Div 1, clause UG-32(e);-
"Torispherical heads made of materials having a specified
minimum tensile strength exceeding 70,000 psi (500 MPa) shall be designed using a value of S equal to 20,000 psi (150 MPa) at room temperature and reduced in proportion to the reduction in maximum allowable stress values at temperature for the material (see UG-23)".
Cheers,
gr2vessels

 

[Thruxton500]

Thanks gr2vessels for your answers.
To clarifie my question re. torispherical heads with mts exeeding 70000 psi.
The question is: The head is calculated with S eqal to 20000 psi @room temp redused in......
A nozzle and its reinforcement areas are located within the sperical portion of head.
Can I use stress values as given in tables in UG-23 when
calculating min. thickness "t" of the sperical portion as per UG-37 to calculate required area "A".
UG-37 does not have any note of reduction of S value.
I assume the cause of reduction of S is to prevent buckling of the knuckle area.

 

[prex]

If I recall correctly, the required thickness of the spherical portion is calculated with the formula for torispherical heads, using M=1. So the limitation on S still holds IMHO.

prex

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[vesselfab]

and

specified minimum tensile must EXCEED 70,000 not be 70,000