Must fixed-roof storage tanks for Class B A liquids be nitrogen-sealed?
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Must fixed-roof storage tanks for Class B A liquids be nitrogen-sealed? The owner asked whether there are any clear regulatory requirements I also want to know if there are any specific requirements here.
Category B A has a flash point of 28°C–45°C; do you think nitrogen blanketing is necessary?
Requirements are specified in SH/T-3007
Class B liquid has a flash point of 28°C–45°C; it is highly prone to flash explosions when exposed to air, and therefore must be sealed under nitrogen.
Article 6.2.2 of the \"Code for Fire Protection Design of Petrochemical Enterprises (2018 Edition)“ (GB 50160-2008): For storing Class A B and Class B A liquids, floating roof tanks or internal floating roof tanks with metal float chambers should be used. For materials with special requirements, or for tanks with a volume of 200 m3 or less, other types of tanks can be employed provided that appropriate safety measures are taken. The floating roof should be selected based on the properties of the flammable liquid and the strength of the material used, and it must comply with the following requirements: 1 When internal floating roof storage tanks with a single tank volume of 5000 m3 or less use floating roofs made of fusible materials, safety measures such as nitrogen protection should be implemented ； 2 For internal floating roof storage tanks with a single tank volume greater than 5000 m3, steel single-disc or double-disc floating roofs should be used ； 3 Floating roof tanks with a single tank volume of 50,000 m3 or more shall use a steel double-disc floating roof. Article 6.2.19: Fixed-roof tanks for Class A and B liquids shall be equipped with flame arresters and vent valves ； Storage tanks for Class A B and Class C liquids that use nitrogen or other gases as a gas seal should also be equipped with emergency pressure relief devices. Not only must a nitrogen seal be installed, but also an emergency pressure relief system.
Is it necessary even if the tank contains only 25 m³ of liquid?
In accordance with the requirements of SH/T3007, the Design Code for Tank Areas in Petrochemical Storage and Transportation Systems, a nitrogen blanketing system should be installed.