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close this bookConducting Environmental Impact Assessment in Developing Countries (United Nations University, 1999, 375 p.)
close this folder9. Emerging developments in EIA
close this folder9.4 Environmental risk assessments
close this folder9.4.11 Guidelines for disaster management planning
View the document(introduction...)
View the document9.4.11.1 Specification
View the document9.4.11.2 Plot plan
View the document9.4.11.3 Hazardous area classification
View the document9.4.11.4 P & I diagrams
View the document9.4.11.5 Storage of inflammable liquids
View the document9.4.11.6 Risk assessment

9.4.11.5 Storage of inflammable liquids

Safety considerations include the location of the tank farm, alternative access, the allowable number of tanks in a tank farm, proper spacing between tanks, proper height of the dike wall, adequate tank farm enclosure capacity, minimum distance between the tank and nearby vicinity to be conformed to, emergency venting in fixed roof tanks, provision of a pump house, provision of floating roof tanks on top of the naphtha and methanol storage tanks, proper velocity at the inlet of methanol or naphtha tanks, provision of nitrogen blanketing for the naphtha or methanol tanks, and, in case of more than one tank, provision of double block and bleed valves with spectacle fluid.

"Non-pressure'' fixed roof tanks should be suitable for working at atmospheric pressure, but be designed for an internal pressure of 7.5 mbar and a vacuum of 2.5 mbar. "Low-pressure'' fixed roof tanks should be designed for an internal pressure of 20 mbar and a vacuum of 6 mbar. "High-pressure'' fixed roof tanks should be designed for an internal pressure of 56 mbar and a vacuum of 7 mbar. See Table 9.10.

Table 9.10 Recommended types of cylindrical tanks for petroleum liquids

Petroleum liquid

Type of tank

Class "I" petroleum (flashpoint below 21 °C/70°F),e.g., motor and aviation gasolines

(a) Floating roof
(b) "Non-pressure" fixed roof with internal floating deck
(c) "Pressure" fixed roof

Class "II" petroleum (flashpoint above 55°C/131 °F)e.g., kerosene, special boiling point liquids

(a) Floating roof
(b) "Non-pressure" fixed roof with internal floating deck
(c) "Non-pressure" fixed roof with "atmospheric" vents

Class "III" petroleum (flashpoint above 55°C/131 °F),e.g., diesel and gas oils, medium and heavy fuel oils, lubricating oils and bitumens

"Non-pressure" fixed roof with "atmospheric" vents. Tanks which contain heavy fuel oils or bitumen are insulated and heated