API 650 Appendix M & F

[neilbarker]

A legal question on how to interpret API-650.

We have a tank with a small internal pressure, therefore Appendix F – Design of Tanks for small internal Pressure- is applicable.
Further point F.1.1 is referring to Appendix M “for maximum design temperatures above 93oC (200 oF), see Appendix M”
The tank has a maximum design temperature greater than 93C, so Appendix M is applicable as well.
M.1.4 says “tanks for small internal pressure in accordance with Appendix F may be used for a maximum design temperature above 93oC (200 oF), subject to the requirements of M.3.6, M.3.7 and M.3.8.” As M.3.7 and M.3.8 are deleted and only M.3.6 is applicable, which says “the structural allowable stresses specified in 5.10.3, including the allowable stresses dependent on the modulus of elasticity, shall be multiplied by the yield strength reduction factors from Table M-1a and M-1b at the maximum design temperature”

The question is: After you've complied with M1.4 do you need to continue and comply with the whole of appendix M. or No further requirements and references of App. M are applicable for Tanks with small internal pressure as API 650 App. F.

 

[IFRs]

If you are building an Annex M tank, you need to satisfy all the requirements of Annex M.
If you are building an Annex F tank, you need to satisfy all the requirements of Annex F.
If your tank is both Annex F and Annex M you need to satisfy all the requirements of both Annexes.
Same for Annex E ( Seismic ) etc.