Nozzle in Ellipsoidal head designed to Code Case 2286-4
Nozzle in Ellipsoidal head designed to Code Case 2286-4
(OP)
Code Case 2286-4 provides alternative rules for designing cylinders, cones, spheres and heads for external pressure.
The design for an ellipsoidal head has reduced the thickness of a convensionally designed VIII-1 head from 53mm to 41mm.
The code case provides rules for locations and sizes of openings in cylinders, but no rules for openings in spheres or ellipsoidal heads. There are general rules for openings but they are contained in a paragraph that only refers to cylinders, so they may not actually be general rules after all.
Does anyone out there have any experience for this code case?
For reference the minimum thickness of this head would be 36mm for PD5500 which does not allow any nozzles to be located in the knuckle of the head. Another words, conventional VIII-1 heads are very sturdy beasts.
The design for an ellipsoidal head has reduced the thickness of a convensionally designed VIII-1 head from 53mm to 41mm.
The code case provides rules for locations and sizes of openings in cylinders, but no rules for openings in spheres or ellipsoidal heads. There are general rules for openings but they are contained in a paragraph that only refers to cylinders, so they may not actually be general rules after all.
Does anyone out there have any experience for this code case?
For reference the minimum thickness of this head would be 36mm for PD5500 which does not allow any nozzles to be located in the knuckle of the head. Another words, conventional VIII-1 heads are very sturdy beasts.





RE: Nozzle in Ellipsoidal head designed to Code Case 2286-4
It may be worth using CC2965, which allows you to use Div. 2 rules with Div. 1 allowable stresses. Div. 2 uses the rules of CC2286 for external pressure design and is clear regarding the reinforcement rules for openings under external pressure (paragraph 4.5).
RE: Nozzle in Ellipsoidal head designed to Code Case 2286-4
RE: Nozzle in Ellipsoidal head designed to Code Case 2286-4
This is a simple head without pressure or temperature cyling or corrossion and has a single opening that has no applied loads. Code Case 2286-4 is ideal if it could only be more specific on the opening requirements.
Whats more, the design is for multiple vessels so the cost of extra thickness adds up with each head.
RE: Nozzle in Ellipsoidal head designed to Code Case 2286-4
RE: Nozzle in Ellipsoidal head designed to Code Case 2286-4
RE: Nozzle in Ellipsoidal head designed to Code Case 2286-4
Both VIII-1 and VIII-2 are sturdy beasts relative to PD 5500.