API-650 Frangible roof
API-650 Frangible roof
(OP)
Hi everybody,
When I am determining the frangible roof area (A), I use the formula in 5.10.2.6.
Checking the roof to top angle compression ring. It is limited to details a-e in fig. F-2. Based on these details, I can determine the participating area for the shell (As) and the participating area for the roof (Ar).
Having these values I can subtract A-As-Ar and the result will be the area for the angle (Aa).
My question arises when the result for the Ar is negative. What does it mean?
I wouldn´t need angle for this kind of configuration?
For this case the participating area for the shell plus the participating area for the roof is exceeding the limit value for frangible joint?
Thanks,
When I am determining the frangible roof area (A), I use the formula in 5.10.2.6.
Checking the roof to top angle compression ring. It is limited to details a-e in fig. F-2. Based on these details, I can determine the participating area for the shell (As) and the participating area for the roof (Ar).
Having these values I can subtract A-As-Ar and the result will be the area for the angle (Aa).
My question arises when the result for the Ar is negative. What does it mean?
I wouldn´t need angle for this kind of configuration?
For this case the participating area for the shell plus the participating area for the roof is exceeding the limit value for frangible joint?
Thanks,





RE: API-650 Frangible roof
RE: API-650 Frangible roof
Anyway I correct a mistake in my post:
My question arises when the result for the Aa is negative. What does it mean?
RE: API-650 Frangible roof
Start with the definition of Aa which is the maximum allowable cross sectional area of the angle. If that value is negative, it is not possible to have a frangible roof for the tank and emergency venting must be provided by other means is required by the customer.
RE: API-650 Frangible roof