willi
Mechanical
- Jul 18, 2001
- 1
I must design a jacketed vessel (Fig. 9-2, Type 1) acc. to Div. 1.
Design data for
shell : FV / 40 psi @ 284°F
jacket : 40 psi @ 284°F
So part of the schell must be designed for 55 psi.
As I understand UG-99 (e), we must hydrotest the jacket based on this differential pressure (1.3x55xstress ratio). This test-pressure will govern all design calculation for part of the shell and the jacket.
Now my question : I cann´t find any way in the code, to do this ´hydrotest calculations´. Do I have to assume an operating load case at ambient temperature or is there a way to consider lower safety margins for hydrotest condition ?
By this I have some headache to use the stress ratio for hydrotests of jackets, because buckling of the shell normally is governed by young´s modulus.
But I´m not so familiar with the code, so maybe I have missed something.
Design data for
shell : FV / 40 psi @ 284°F
jacket : 40 psi @ 284°F
So part of the schell must be designed for 55 psi.
As I understand UG-99 (e), we must hydrotest the jacket based on this differential pressure (1.3x55xstress ratio). This test-pressure will govern all design calculation for part of the shell and the jacket.
Now my question : I cann´t find any way in the code, to do this ´hydrotest calculations´. Do I have to assume an operating load case at ambient temperature or is there a way to consider lower safety margins for hydrotest condition ?
By this I have some headache to use the stress ratio for hydrotests of jackets, because buckling of the shell normally is governed by young´s modulus.
But I´m not so familiar with the code, so maybe I have missed something.
