Design of fire shields for inlet and outlet isolation valves of storage tanks in tank farms
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Gentlemen, with the construction of new projects currently underway, are pneumatic or electric valves better for use in storage tanks in tank farms? Are there any regulatory requirements? Is it necessary to design a fire shield? The specifications I have found are attached; as for determining which valves are emergency shut-off valves, the specifications require that such valves be equipped with fire protection measures, with fire shields being the preferred option
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Gentlemen, with the construction of new projects currently underway, are pneumatic or electric valves better for use in storage tanks in tank farms? Pneumatic priority. Are there any regulatory requirements? Is it necessary to design a fire shield? There is no requirement; it is not mandatory (see below). The standards I have found so far are attached. As for determining which valves are emergency shut-off valves, the standards specify that such valves should have fire protection measures in place, with fire shields being the preferred option. ESD valves represent a general term for functions that include process interlocks as well as fire isolation and shutdown mechanisms. Regarding fire shields for electric valves, the power/control cables that are installed exposed in the fire compartment must be flame-resistant; fire shields can be used for this purpose. Pneumatic valves can be equipped with fusible plugs, or the valve tubing can be made of plastic, allowing it to close automatically when air is lost due to a fire. At this time, a fire shield is not necessary. Pneumatic valves that need to remain open in case of a fire, such as the water injection valves for spherical tanks or the valves used for transferring liquid hydrocarbons during a fire, must be equipped with fire shields to ensure that they stay open under fire conditions.
The cutoff valve is only specified in 6.13 of the \"Safety Technical Regulations for Vertical Circular Welded Steel Storage Tanks\"; there are no detailed requirements in either the petrochemical regulations or the oil depot regulations. In fact, such valves are generally operated pneumatically as emergency cutoff valves, as pneumatic control enables easy implementation of fail-safe mechanisms, and the shutdown time can also meet the requirements set by the regulations. If an electric version is used, a backup power source is also required; in some cases, the fireproof cover needed for protection can be more expensive than the valve itself
API2218 specifies the scope of emergency valves: these are the emergency valves used in fire scenarios, including the suction valves that supply large towers, collection tanks, and feed buffer tanks.