API RP 581 - 3rd Ed.2016 - Add.2-2020 - Risk-Based Inspection Methodology

3-24 API RECOMMENDED PRACTICE 581
2) Calculate the consequence area using Equation (3.52).
1 fact
CA − a ( mass
− n )
⎛ −
= ⎡ ⋅ ⎤⋅⎜ ⎞
⎣ ⎦
⎟
(3.52)
⎝ ⎠
AIL INST AIL INST
b
mit
inj,
n
⎢
⎥ eneffn
IC
l) STEP 8.12—For each release hole size, calculate the instantaneous/continuous blending factor, fact
n
,
using Equations (3.19), (3.20), or (3.21), as applicable. Instantaneous/continuous blending is not required
for TYPE 1 fluids. For TYPE 1 fluids, use the component damage and personnel injury areas based on
release type.
m) STEP 8.13—Calculate the AIT blending factor,
applicable.
AIT
fact
, using Equations (3.24), (3.25), or (3.26), as
n) STEP 8.14—For TYPE 0 fluids, calculate the continuous/instantaneous blended consequence areas for
TYPE 0 fluid components using Equations (3.53) through (3.56) based on the consequence areas
calculated in STEPs 8.4, 8.5, 8.6, 8.7, 8.8, 8.9, 8.10, and 8.11, and the continuous/instantaneous blending
factor,
fact
IC
n
, from STEP 8.12. Instantaneous/continuous blending is not required for TYPE 1 fluids. For
TYPE 1 fluids, use the component damage and personnel injury areas based on release type from STEPs
8.4 to 8.11.
( )
CA = CA ⋅ fact + CA ⋅ − fact
(3.53)
AIL AIL−INST IC AIL−CONT IC
cmd , n cmd , n n cmd , n
1
n
( )
CA = CA ⋅ fact + CA ⋅ − fact
(3.54)
AIL AIL−INST IC AIL−CONT IC
inj, n inj, n n inj, n
1
n
( )
CA = CA ⋅ fact + CA ⋅ − fact
(3.55)
AINL AINL−INST IC AINL−CONT IC
cmd , n cmd , n n cmd , n
1
n
( )
CA = CA ⋅ fact + CA ⋅ − fact
(3.56)
AINL AINL−INST IC AINL−CONT IC
inj, n inj, n n inj, n
1
n
o) STEP 8.15—Calculate the AIT blended consequence areas for all components using Equations (3.57)
and (3.58) based on the consequence areas determined in STEP 8.14 and the AIT blending factors,
AIT
fact calculated in STEP 8.13. The resulting consequence areas are the component damage and
flam
personnel injury flammable consequence areas, CA
cmd , n
and
,
selected in STEP 2.2.
( )
flam AIL AIT AINL AIT
cmd , n cmd , n cmd , n
CA
flam
inj n
, for each release hole sizes
CA = CA ⋅ fact +CA ⋅ 1- fact
(3.57)
( )
CA = CA ⋅ fact +CA ⋅ 1- fact
(3.58)
flam AIL AIT AINL AIT
inj, n inj, n inj,
n