API RP 1604-2021 pdf free download

API RP 1604-2021 pdf free download.Closure of Underground Petroleum Storage Tanks.
3? Terms? and? Defnitions For the purposes of this document, the following defnitions apply. 3.1 approved Acceptable to the authority having jurisdiction. 3.2 authority having jurisdiction (AHJ) An organization, ofce, or individual responsible for enforcing the requirements of a code or standard, or for approving equipment, materials, an installation, or a procedure. 3.3 change of service Conversion of the UST to storage of a non-regulated substance. 3.4 clean (cleaning) The removal of all product, vapor, sludge, and residue from a tank, and washing, rinsing, and drying a tank so that no product or residue remains on any tank surfaces (shell, bottom, piping, appurtenances, etc.). 3.5 combustible? gas? indicator An instrument used to sample the atmosphere to indicate if any fammable (combustible) vapors/gases are present; determine the composition of hydrocarbon gas and air mixtures; and indicate the concentration of vapor/ gas present in the atmosphere as a percentage of the lower explosive (fammable) limit (LEL). 3.6 degassing The process of collecting, oxidizing, or treating vapors and gases expelled from an underground tank to prevent or reduce the amount of organic volatile compounds released into the atmosphere during vapor-freeing operations. 3.7 empty (emptied) A tank that has no (standing) product remaining in the tank and is ready for vapor freeing and cleaning. 3.8 explosive? (fammable)? range The range of concentrations of fammable vapor-in-air, between the lower explosive (fammable) limit (LEL) and the upper explosive (fammable) limit (UEL), that will propagate fame if ignited.
3.9 hot work Any work that has the potential to produce enough thermal energy to provide an ignition source in an area where a potential exists for a fammable gas or vapor in-air atmosphere in the explosive (fammable) range to occur, such as drilling, grinding, cutting, abrasive blast cleaning, etc. 3.10 inerting A technique by which the atmosphere in a tank or container is rendered nonignitable or nonreactive by the addition of an inert gas. 3.11 lower? explosive? (fammable)? limit? (LEL) The minimum concentration expressed as a volume (percentage) of a vapor-in-air below which propagation of fame does not occur on contact with an ignition source; generally considered to be “too lean to burn.” 3.12 petroleum-contaminated soil Any earthen material or artifcial fll that has human or natural alteration of its physical, chemical, biological, or radiological integrity resulting from the introduction of crude oil, or any fraction or derivative thereof (such as gasoline, diesel, or motor oil). 3.13 purging The process of adding an inert gas to a combustible mixture to reduce the concentration of oxygen below the minimum oxygen content (MOC). For many gases, the MOC is ~10 %. 3.14 sludge Undesirable materials that accumulate in the bottom of underground tanks and are removed for disposal, usually consisting of heavy petroleum products or a mixture of hydrocarbons, residue, and water, that may be fammable, hazardous, and/or toxic. 3.15 storage tank Any vessel having a liquid capacity that exceeds 60 gal (230 L), is intended for fxed installation, and is not used for processing. 3.16 underground storage tank system (UST) A tank and any underground piping connected to the tank that has at least 10 % of its combined volume underground. 3.17 upper? explosive? (fammable)? limit? (UEL): The maximum concentration expressed as a volume (percentage) of a vapor-in-air above which propagation of fame does not occur upon contact with an ignition source; generally considered “too rich to burn.”