Imperfections discussed in 6.4.6 with dimensions referenced in Table 3 of ANSI B16.5 most likely could be porosity, chatter marks from machining, micro-shrinkage defects, etc. Basically, the term defect in this case is a void on the flange face surface.
At the column A and column B (table 3) are there values for imperfections 3 mm and 1,5 mm. That imperfections could be on the serrations ? If yes, it could be there a porosity so big than 3 mm ?
What does it means "maximun radial projection of imperfection which are no deeper than the bottom of the serrations ?
Yes, to your first question. Radial means thru the thickness dimension of the flange, and in your case, the void or imperfection cannot protrude in depth beyond the base of the serrations. Column B is for voids that extend past the depth radially of the serration groove.
So, the imperfections are very big. Can I have a porosity of 3 mm on the serrations, since that they are not deeper than the grooves of the serrations. Or, porosity of 1,5 mm that they are deeper than the grooves of the serrations. But the serrations are not deeper than 0,1 mm.
We don´t accept imperfections any size on the serrations. Because that, we have rejected many castings. Frequently the castings has small porosities ( diameter 0,5 mm ) on the serrations. If Radial projection is the depth thru the thickness of the flange, then what size in diameter the porosity culd have ?
firmino;
Please obtain a copy of B16.5, and read sectnio 6.4.6 carefully. All of the information is there, you just need to spend some time to review it.