NFPA 59A-2001 Standard for the Production, Storage, and Handling of Liquefied Natural Gas (LNG).
1.7.10 Dike. A structure used to establish an impounding area. 1.7.11 Failsafe. A design feature that provides for the mainte- nance of safe operating conditions in the event of a malfunc- tion of control devices or an interruption of an energy source. 1.7.12 Fired Equipment. Any equipment in which the com- bustion of fuels takes place; equipment can include fired boil- ers, fired heaters, internal combustion engines, certain integral heated vaporizers, the primary heat source for remote heated vaporizers, gas-fired oil foggers, fired regeneration heaters, and flared vent stacks. 1.7.13 Fixed Length Dip Tube. A pipe that has a fixed open end inside a container at a designated elevation that is intended to show a liquid level. 1.7.14 Flame Spread Rating. The flame spread rating of materials as determined in accordance with NFPA 255, Stan- dard Method of Test of Surface Burning Characteristics of Building Materials, or ULC Standard CAN4-S102, Surface Burning Charac- teristics of Building Materials and Assemblies, 1988, as appropriate. 1.7.15 G. The normal or standard constant of gravity; at sea level, “G” equals approximately 32.2 ft/sec/sec (9.81 m/sec/sec). 1.7.16 Hazardous Fluid. A liquid or gas that is flammable, toxic, or corrosive. 1.7.17 Impounding Area. An area defined through the use of dikes or the site topography for the purpose of containing any accidental spill of LNG or flammable refrigerants. 1.7.18 Liquefied Natural Gas (LNG). A fluid in the liquid state that is composed predominantly of methane and that can contain minor quantities of ethane, propane, nitrogen, or other components normally found in natural gas. 1.7.19 LNG Plant. A plant whose components are used to store liquefied natural gas and may also condition, liquefy, or vaporize natural gas. Flammable liquid and flammable refrigerant storage tanks shall not be located within an LNG container impound- ing area. 2.2.2 Impounding Area and Drainage System Design and Capacity. Impounding areas serving LNG containers shall have a minimum volumetric holding capacity, V, including any use- ful holding capacity of the drainage area and with allowance made for the displacement of snow accumulation, other con- tainers, and equipment, in accordance with the following: (1) For impounding areas serving a single container, V equals the total volume of liquid in the container, assuming the container is full. (2) For impounding areas serving more than one container with provision made to prevent low temperature or fire exposure resulting from leakage from any one container served from causing subsequent leakage from any other container served, V equals the total volume of liquid in the largest container served, assuming the container is full. (3) For impounding areas serving more than one container without provision made in accordance with, V equals the total volume of liquid in all containers served, assuming all containers are full.NFPA 59A pdf download.