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.
