API-650 11th Ed Addendum 2 - Table 5-21b
API-650 11th Ed Addendum 2 - Table 5-21b
(OP)
Is anyone aware of an errata published for the equations in this table? (If so an official URL to such a document would be most appreciated.)
Several equations appear to be "copied" from 5-21a (design pressure+wind, design pressure+seismic, and frangibility pressure). These appear to be incorrect for "US Customary Units".
Also, I've heard a number of reports that the equation for the seismic uplift in this table uses the wrong moment from Appendix E ?
Several equations appear to be "copied" from 5-21a (design pressure+wind, design pressure+seismic, and frangibility pressure). These appear to be incorrect for "US Customary Units".
Also, I've heard a number of reports that the equation for the seismic uplift in this table uses the wrong moment from Appendix E ?
Richard Ay
COADE, Inc.





RE: API-650 11th Ed Addendum 2 - Table 5-21b
Ditto for the design pressure + seismic.
In either case, that is 490 pcf/62.4 pcf, converting inches of steel to inches of water.
In the frangibility pressure, the 0.08 should be an 8, and there should be a 4.08 factor as in the equations above. That is pi/4x62.4/12.
The seismic moment should be the Mrw, not the Ms. I don't think they got the wrong moment in there, they just didn't get the terminology changed when they added the equation for Mrw in Appendix E.
RE: API-650 11th Ed Addendum 2 - Table 5-21b
I'm concerned about making these obvious corrections, then trying to justify the calculations to someone who says "...but that isn't what the Code states."
Richard Ay
COADE, Inc.