ASME SEC.VIII Div.1 Appendix-3 defination of the MAWP

yhcxdh

Dear all,

This refers to ASME SEC.VIII Div.1 Appendix-3 defination of the MAWP

maximum allowable working pressure: the maximum gage pressure permissible at the top of a completed vessel in its normal operating position at the designated coincident temperature for that pressure. This pressure is the least of the values for the internal or external pressure to be
determined by the rules of this Division for any of the pressure boundary parts, including the static head thereon,using nominal thicknesses exclusive of allowances for corrosion and considering the effects of any combination of loadings listed in UG-22 that are likely to occur (see UG-98) at the designated coincident temperature [see UG-20(a)].

Output of software :

Max. Allowable Working Pressure at given Thickness, corroded [MAWP]:
Less Operating Hydrostatic Head Pressure of 0.098 bars = (2*S*E*t)/(Kcor*D+0.2*t) per Appendix 1-4 (c)
= (2*117.90*1.00*10.6000)/(0.985*556.4000+0.2*10.6000)
= 45.432 - 0.098 = 45.334 bars

I want to just clarify that in software when we calculate MAWP of any component we substract opearting static head but above defination says it shall be including static head.

I know this is very basic question but the code wording of "including static head" & software output makes me confused.

Please clarfiy that are both the things are correct or not?