If you have even a basic understanding of Part 5 of Section VIII div 2 than you would be able to understand how the Div 3 material requirements work within a couple of minutes.
Part 5 of ASME VIII Div 2 and Div 3 require a mentor that is close by all the time.
Could the difference between the material properties on the material certificate and and the Properties specified in Section II be considered a Safety Margin?
Many of the properties specified in Section II cover all thicknesses of a material. However typically thinner plate has higher yeild...
How do you come to your conclusion?
It sounds a bit counter intuative when thinking of adding a corrosion allowance to a stainless steel nozzle that is welded into a carbon steel shell.
But in the step after calculating tb1, the nozzle can not be thinner than the lesser of the new shell (tb1)...
It could be that the design pressure is designed for sustained pressure loading only.
And the Operating (working) pressure includes for fatigue, in which case increasing the operating pressure could be hazardous.
Is the pressure/temperature cyclic?
Thanks TGS4,
Dividing the CYCLES by FSRF is wildly wrong.
Where do you get the 2/20 from for the smooth bar method?
I assumed that because the Welded Fatigue curves of Div 2 use standard deviations (3 SD as deault), then the smooth bar curve is good for 3 SD.
The S-I curves in PD 5500 are for 2 standard deviations (for instances where additional inspection is not required).
ASME VIII Div 2 uses 3 Standard Deviations as default. So 200 cycles / 0.6 ~= 333 cycles for PD 5500. (0.6 roughly converts 3 SD to 2 standard devs.)
Is the 200 cycle / 1900...
I think the second paragraph of UG-29c is for rings in general (The first paragraph applies to internal rings only). I think Compress brings it up as a deficiency as it is unable to carry out the checks specified in the second paragraph of UG-29c. You have to carry out these checks manually...
See Section U-1(c)(2). It says pressure vessels for human occupancy are not covered by ASME VIII. However if the pressure vessel (that is the steel fabricated vessel without the acrylic viewport) is designed in accordance with ASME VIII it can be given a U Stamp. PVHO allows you to design the...
You may be able to get some of the way with ASME VIII Div 1, however with the complex stresses I expect U-2(g) will be required.
With respect to U-2(g), have a look at Page 31 of the NASA document http://www.nasa.gov/centers/dryden/pdf/88569main_H-2206.pdf. It has a fixed sqaure plate with a...
If the head is seamless or 100% X-Rayed:
If the Shell-Head circ seam is 100% X-Ray or Modified Spot in accordance with UW-11(a)(5)(b) then the head can have a weld efficiency of 1.00.
If the shell-head seam has Normal Spot X-Ray or no Radiography at all then the head can have a weld efficiency...
There is no mention of distance between welds in UG-36(c)(3). The only mention is in UW-14(d), which says any small openings that haven't had a reinforcing calculation must be atleast 13mm from from Catergory A, B or C welds in a shell thickness less then 38mm. But it can be within 13mm if you...
Fig e is for a cylinder. I don't think your hemispherical head is a cylinder.
Fig f is for a sphere. I think your hemispherical head is a sphere.
Read the Figure Headings and study some fundamental engineering equations. (i.e. stress(sphere)=PR/2t and Stress(cylinder)=PR/t)
ASME VIII Div 1 doesn't address distance between welds at all.
And the answer is different for every material.
For instance Aluminium 5083 is not affected by welds being close together or on top of each other.
Carbon steel is a different story. And then PWHT can be taken into account...
Okay, I have found with my limited use of linear FEA that it's stress catagorisation and lineaisation rules are a bit "one size fits all". It does a great job when conducted competently but as it doesn't model the non-linear stress/strain beyond yield accurately it is a bit clunky and has allot...
I'm not familiar with bursting tests, but if you are testing something to failure then doesn't that establish the highest possible MAWP? Expecially as the materials actual strength can be in the region of 30% more then that specified by ASME II.
Wouldn't any other method including a...
