Are you sure that is the right interpretation number ? That interpretation does not have anything to do with manufacturing tolerence.
Here it is:
Interpretation: 2-27
Subject: Area of Reinforcement for Contoured Integrally Reinforced Branch Connections
Date Issued: October 26, 1983
File: 1681 (B31 83-034)
Question: Do the rules for extruded outlets apply to contoured integrally reinforced fittings? If not,
what are the correct equations, indicated in ANSI/ASME B31.1, B31.2, B31.3, B31.4, and B31.8, to
be used in determining the limits of area reinforcement for contoured integrally reinforced branch
connecting fittings (e.g., Weldolet) and extruded outlets?
Reply: The contoured integrally reinforced fitting is not an extruded outlet. The equations set forth
in the B31 Codes for determining the reinforcing limits of an extruded outlet do not apply in determining
the reinforcing limits of a contoured integrally reinforced fitting.