Thank you, CodeJackal, for a good post. Since it is obviously such sound logic, it should really apply Sec. VIII Div. 1 design as well. I see no reason why the same approach cannot be taken in that case, when everyone knows that a conservative design by VIII-1 is always an overdesign, and so a...
@JStephen: Thanks for reminding me, you are correct: we can utilize excess thickness available in the shell at least to partly compensate for the loss in the opening, such that only the balance of mass needs to be made-up by way of the pad. [speaking in terms of the BPV Code]
@weldtek:
Now that sets me thinking, again !
So, the heads as delivered by the head manufacturer will have the ordered thickness at wherever is the minimum? Which would mean there's nothing the designer needs to factor-in for thinning?
It is generally believed that upto ten per cent...
Actually there are two ways of looking at it. When ASTM specifies a lower threshold of a constituent, it implies that (i) the rest of the constituents listed shall make up the difference OR (ii) the percentage shortfall accounts for trace materials which do not influence the properties.
If...
The basic principle was supposed to be that you only have to replace the quantity of metal lost in the opening by providing a reinforcing pad of the same mass. If this is the only criterion, then one ought to have no doubts on the reinforcement requirement calculations.
Further comments/...
Life was certainly much better before I had to know that thinning could be at places other than the knuckle zone. Do we have to live with uncertainty now on, then? How would one provide thinning allowance for design?
I have a feeling there's a strong point here in the post of Ray1959. Let me continue to read postings and also do a re-read before further comment. Very interesting issue at hand.
On a slightly different note, though:
In case of ASME Sec. VIII Div. 1 BPV Code, the design is intended for internal pressures above 15 psi (g, I believe). If the int. pr. is "atmospheric," the vessel can still be desiged as per code, I am told.
The formulas result in such small values of...
Thank you, JStephen, that's most helpful.
Basically, I wanted to know what I should understand by "design as per Appx A."
At this stage, it may not be possible for me to do a serious study of the various design methods in the std, compare them and understand the differences.
Any further...
PS: I did do a simple search on eng-tips forums without much success. This question may have been answered in another thread earlier. Pointers to the relevant thread if any, will also be most welcome.
Tx in adv
panduru
What would be a suitable software/ tutorial/ demo to start learning design of above ground storage tanks as per API 650 Appendix A?
Is the "one-foot method" (whatever it is) an acceptable alternative to Appendix A, or is it intended for a different purpose?
Every kind of lead, tip or...
