API-650 Table 5-21b
API-650 Table 5-21b
(OP)
Comparing 11th Edition Addendum 2 to Addendum 1:
In Addendum 2 the equations in Table 5-21b for "design pressue + wind", "design pressure + seismic", and "frangibility pressure" all have a constant of "0.08" as the mulitiplier for "th". However, the same equations in Addendum 1 use a constant of "8". The 0.08 constant is used in the SI version, Table 5-21a. I presume this is a mistake in Addendum 2, and the constant in Table 5-21b should still be "8" ?
For the frangibility pressure, I also assume the loss of the "4.08" multiplier is a mistake ?
In Addendum 2 the equations in Table 5-21b for "design pressue + wind", "design pressure + seismic", and "frangibility pressure" all have a constant of "0.08" as the mulitiplier for "th". However, the same equations in Addendum 1 use a constant of "8". The 0.08 constant is used in the SI version, Table 5-21a. I presume this is a mistake in Addendum 2, and the constant in Table 5-21b should still be "8" ?
For the frangibility pressure, I also assume the loss of the "4.08" multiplier is a mistake ?
Richard Ay
COADE, Inc.





RE: API-650 Table 5-21b
RE: API-650 Table 5-21b
The 4.08 is pi/4 x 62.4/12.
I think your assumptions are correct.
RE: API-650 Table 5-21b
The pressure P and 0.08th in kPa mutliplied by diameter in meters result in units of kN. The wind and seismic moments are in N-m and W1, W2 and W3 are in kN and the resulting uplift loads are in N?
Believe Ms & Mw should be in kN-m and the uplift forces are in kN. Can anyone confirm.
Add 2 does not do much to help clarify these as the units all remained the same, however a factor of 785 was added. Where does this factor come from?