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

RISK-BASED INSPECTION METHODOLOGY, PART 3—CONSEQUENCE OF FAILURE METHODOLOGY 3-111
ii) Calculate the Hopkinson-scaled distance, R
HS
function of the distance from the BLEVE chosen above,
, using Equation (3.171). This parameter is a
bleve
xs
cmd
.
iii)
iv)
Calculate the side-on overpressure, P
SO
, at the Hopkinson-scaled distance, R
HS
, using
Equation (3.170).
Adjust the distance, xs
overpressure, P
SO
bleve
cmd
, accordingly, and repeat the above steps until the side-on
, is equal to 34.5 kPa (5.0 psi).
bleve
5) Calculate the component damage consequence area, CA , using Equation (3.196).
f , cmd
6) For the personnel injury consequence area, a probit equation based on building collapse (see Section
5.8.5.5). This probit equation is used to determine the safe distance, xs , from the BLEVE using
the following five-step iterative procedure.
i) Guess at an acceptable personnel injury distance from the BLEVE,
ii) Calculate the Hopkinson-scaled distance, R
HS
function of the distance from the BLEVE chosen above,
bleve
inj
bleve
xs .
inj
, using Equation (3.171). This parameter is a
bleve
xs .
inj
iii)
Calculate the side-on overpressure, P
SO
, at the Hopkinson-scaled distance, R
HS
, using
Equation (3.170).
iv) Calculate the probit value, Pr , using Equation (3.172).
v) Adjust the distance, xs
equal to 5.0.
bleve
inj
, accordingly, and repeat the above steps until the probit value is
bleve
7) Calculate the personal injury consequence area, CA , using Equation (3.174).
f , inj
d) STEP 10.4—For each hole size, sum up the consequence areas for each of the nonflammable, nontoxic
events using Equation (3.198) and Equation (3.199). The resultant component damage consequence
area is nfnt
nfnt
CA , and personnel injury area is
f , cmd , n
CA .
f , inj,
n
e) STEP 10.5—Calculate the final, probability weighted nonflammable, nontoxic consequence areas,
nfnt
nfnt
CA and
f , cmd
CA , using Equation (3.200) and Equation (3.201).
f , inj
5.11 Determine the Component Damage and Personnel Injury Consequence Areas
5.11.1 Overview
The final consequence areas for component damage and personnel injury are the maximum areas of those
calculated for: