API-650 11th Ed Addendum 2 - Table 5-21b

[richay]

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 ?

Richard Ay
COADE, Inc.

 

[JStephen]

Checking them just now, it looks like in the pressure+wind, the 0.08 factor should be an "8".
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.

 

[richay]

Those were my conclusions also. Is there an "official" errata available?

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.