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 VIII 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.
My design software (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, the software 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°).
I cannot find in literature any other example of this kind of problem.
Does anyone know which is the “right” interpretation of the ASME code about this issue?
Does anyone have some experience with tilted nozzle in order to explain the reason of this two different ways of calculation?
How do you face the reinforcement problem?
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.
I posted a sketch of the problem at this URL
Please check it out.
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 VIII 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.
My design software (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, the software 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°).
I cannot find in literature any other example of this kind of problem.
Does anyone know which is the “right” interpretation of the ASME code about this issue?
Does anyone have some experience with tilted nozzle in order to explain the reason of this two different ways of calculation?
How do you face the reinforcement problem?
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.
I posted a sketch of the problem at this URL
Please check it out.
Giangiacomo
