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

PART 1—INTRODUCTION TO RISK-BASED INSPECTION METHODOLOGY 1-11
3.1.76
target date
Date where the risk target is expected to be reached and is the date at or before the recommended
inspection should be performed.
3.1.77
TNO multi-energy model
A blast model based on the theory that the energy of explosion is highly dependent on the level of
congestion and less dependent on the fuel in the cloud.
3.1.78
TNT equivalency model
An explosion model based on the explosion of a thermodynamically equivalent mass of trinitrotoluene (TNT).
3.1.79
transmissivity
The fraction of radiant energy that is transmitted from the radiating object through the atmosphere to a target;
the transmissivity is reduced due to the absorption and scattering of energy by the atmosphere itself.
3.1.80
toxic chemical
Any chemical that presents a physical or health hazard or an environmental hazard according to the
appropriate material safety data sheet (MSDS). These chemicals (when ingested, inhaled, or absorbed
through the skin) can cause damage to living tissue, impairment of the central nervous system, severe
illness, or in extreme cases, death. These chemicals may also result in adverse effects to the environment
(measured as ecotoxicity and related to persistence and bioaccumulation potential).
3.1.81
vapor cloud explosion
VCE
When a flammable vapor is released, its mixture with air will form a flammable vapor cloud. If ignited, the
flame speed may accelerate to high velocities and produce significant blast overpressure.
3.2 Acronyms and Abbreviations
ACFM
ACSCC
AE
AEGL
AHF
AIHA
AIT
ASME
AST
ASTM
AU
AWWA
alternating current field measurement
alkaline carbonate stress corrosion cracking
acoustic emission
acute exposure guideline level
anhydrous hydrofluoric acid
American Industrial Hygiene Association
autoignition temperature
American Society of Mechanical Engineers
atmospheric storage tank
American Society for Testing and Materials
additional uncertainty
American Water Works Association