UG-37, Area A1
UG-37, Area A1
(OP)
Well, I'm having a bit of disagreement with my software.
Is there any circumstance where it is not permitted or is improper to use the second expression in Fig. UG-37.1 for A1?
The case in question involves opening reinforcement in a flat head when restricting the limits of reinforcement, for which my software seems to disregard the second expression, which yields the larger value of A1. It only outputs one value for A1 so it is impossible to know what it calculates for the other. Thanks, programmers.
I'm kind of of the opinion that, since the second expression does not involve "d" it is not modified when the limits are restricted. I suppose it could be reduced by the ratio of the restricted limits to the permitted limits ("d"), but in this case it still yields the larger value for A1.
I'm wondering if there might be an interpretation to the effect that the second expression for A1 be disregarded under some circumstances.
Any takers?
Regards,
Mike
Is there any circumstance where it is not permitted or is improper to use the second expression in Fig. UG-37.1 for A1?
The case in question involves opening reinforcement in a flat head when restricting the limits of reinforcement, for which my software seems to disregard the second expression, which yields the larger value of A1. It only outputs one value for A1 so it is impossible to know what it calculates for the other. Thanks, programmers.
I'm kind of of the opinion that, since the second expression does not involve "d" it is not modified when the limits are restricted. I suppose it could be reduced by the ratio of the restricted limits to the permitted limits ("d"), but in this case it still yields the larger value for A1.
I'm wondering if there might be an interpretation to the effect that the second expression for A1 be disregarded under some circumstances.
Any takers?
Regards,
Mike





RE: UG-37, Area A1
I did find VIII-1-83-359, although I don't know if it's relevant to your design:
Question (1): For the calculation of A1 in UG-37, is tn = 0 when a pipe nipple is screwed into a flat head a distance which is not the full thickness of the head?
Reply (1): Yes.
RE: UG-37, Area A1
The programs I normally use will allow a user to specify a lesser limit of reinforcement both in plane and up the nozzle neck. This in turn reduces the contribution of excess material in the shell (A1) and in the nozzle neck (A2).
Regards,
Mike
RE: UG-37, Area A1
RE: UG-37, Area A1
Regards,
Mike
RE: UG-37, Area A1
To document, if anyone is interested:)
Both expressions for A1 are identical except for the first term, which represents the limits of reinforcement as stated in UG-40(b).
Since the material inside the opening is not available for reinforcement the dimension along the wall either side of the opening can be written as either (2 * d - d), which reduces to d, or as 2 * (Rn + tn + t) - d, which reduces to 2 * (tn + t) since d = 2 * Rn.
If restricting the limits, the restricted limit, call it Dr, presumably replaces the larger of 2 * d or 2 * (Rn + tn + t) such that the first term for A1 becomes (Dr - d) and the larger expression for A1 still governs.
I say presumably because I haven't checked a large number of cases, but it seems reasonable.
Regards,
Mike