ggroppi
Mechanical
- Sep 15, 2006
- 10
Hi!
Has anyone experienced problems in verifying reinforcement area requirements in tilted nozzles?
I’ve some troubles with a 45° degrees downward oriented nozzle type 9.
In computing the limits of reinforcement I usually refer to Article D-5 of ASME VII div.2.
So I find a limit in the normal to the vessel axis direction, then accordingly to ASME VIII- div 2 AD-540.2 I consider as reinforcement area the heavy barrel area comprised underneath the normal to the vessel wall limit H, that for a 45° tilted nozzle has the shape of a parallelogram. I believe that compress in calculating this area is taking into account, in favour of safety, a smaller area than the one actually available. In fact, in cross sectional view, Compress computes the area taking the normal to the vessel limit H times the heavy barrel thickness, tn - trn i.e. Area = H * (tn - trn), which is the area of a rectangle smaller than the parallelogram; while I’m used to compute the whole area of the parallelogram i.e. A = (H/sin beta) * (tn - trn), where beta is the inclination angle of the tilted nozzle (in my case 45°).
Can any one explain to me the reason of this choice? Is it a different interpretation of the ASME code?
I remark that this different way of computing the area leads to two different results, what for me is adequate result in a “Not adequate” reinforcement for Compress, with the obvious consequences in the deficiencies report.
Giangiacomo
Has anyone experienced problems in verifying reinforcement area requirements in tilted nozzles?
I’ve some troubles with a 45° degrees downward oriented nozzle type 9.
In computing the limits of reinforcement I usually refer to Article D-5 of ASME VII div.2.
So I find a limit in the normal to the vessel axis direction, then accordingly to ASME VIII- div 2 AD-540.2 I consider as reinforcement area the heavy barrel area comprised underneath the normal to the vessel wall limit H, that for a 45° tilted nozzle has the shape of a parallelogram. I believe that compress in calculating this area is taking into account, in favour of safety, a smaller area than the one actually available. In fact, in cross sectional view, Compress computes the area taking the normal to the vessel limit H times the heavy barrel thickness, tn - trn i.e. Area = H * (tn - trn), which is the area of a rectangle smaller than the parallelogram; while I’m used to compute the whole area of the parallelogram i.e. A = (H/sin beta) * (tn - trn), where beta is the inclination angle of the tilted nozzle (in my case 45°).
Can any one explain to me the reason of this choice? Is it a different interpretation of the ASME code?
I remark that this different way of computing the area leads to two different results, what for me is adequate result in a “Not adequate” reinforcement for Compress, with the obvious consequences in the deficiencies report.
Giangiacomo