Every attempt is made for accuracy in every portion of the guide. It pains me to find mistakes, but I post them here in an effort for complete clarity and most importantly to aid in better exam prep.
I greatly appreciate any and all feedback from users in improving this guide. All of these updates are incorporated for future editions.
2019 PE Prep Guide Errata:
Formula 2.3 (p41): Flame height for wall configurations should use convective heat release rate, not total heat release rate. [ zl=0.166(Qc*/k)^0.4, not zl=0.166(Q*/k)^0.4 ]. This is incorrectly identified in FPH p18-45 Formula (2). NFPA 92 references convective heat release rate and is a recognized, adopted standard.
Formula 8.16 (p79): Temperature inputs should be in Rankine (R), not Fahrenheit (deg F)
Question #4 (p95): Each component in the problem should have a "probability of failure" and not a "failure rate". These are two separate terms, and mean two different things. In this problem, for example, OS&Y valve should say "closed/failed: 0.5% probability of failure."
Although the failure rate, λ(t), is often thought of as the probability that a failure occurs in a specified interval, it is not actually a probability because it can exceed 1.0. A probability, on the other hand, cannot exceed 100%. Problems asking for "probability of failure or success" are different than problems asking for a "failure rate" or "success rate" of a system.
Question #156: The question would have to clarify which occupancy is used. Mercantile - Bulk Retail results in a different answer than just Mercantile.
Index (p379): The item "Separation Distance of Storage Tank" at page 263 no longer applies.
[End of Errata]
I greatly appreciate any and all feedback from users in improving this guide. All of these updates are incorporated for future editions.
2019 PE Prep Guide Errata:
Formula 2.3 (p41): Flame height for wall configurations should use convective heat release rate, not total heat release rate. [ zl=0.166(Qc*/k)^0.4, not zl=0.166(Q*/k)^0.4 ]. This is incorrectly identified in FPH p18-45 Formula (2). NFPA 92 references convective heat release rate and is a recognized, adopted standard.
Formula 8.16 (p79): Temperature inputs should be in Rankine (R), not Fahrenheit (deg F)
Question #4 (p95): Each component in the problem should have a "probability of failure" and not a "failure rate". These are two separate terms, and mean two different things. In this problem, for example, OS&Y valve should say "closed/failed: 0.5% probability of failure."
Although the failure rate, λ(t), is often thought of as the probability that a failure occurs in a specified interval, it is not actually a probability because it can exceed 1.0. A probability, on the other hand, cannot exceed 100%. Problems asking for "probability of failure or success" are different than problems asking for a "failure rate" or "success rate" of a system.
Question #156: The question would have to clarify which occupancy is used. Mercantile - Bulk Retail results in a different answer than just Mercantile.
Index (p379): The item "Separation Distance of Storage Tank" at page 263 no longer applies.
[End of Errata]
