Is it necessary to equip the emergency shut-off valve with a fire shield? Can this amazing thing really work?

According to the standard T∕HGJ 12402-2021 \"Design Standards for Emergency Isolation Control Valves in Petrochemical Plants\", fire shields are required in these five common situations: 1. When a pneumatic actuator with a spring-return single-acting cylinder is used, a fusible plug is installed on the pneumatic control pipeline or the cylinder; during a fire, the fusible plug melts, the cylinder loses pressure, and the emergency isolation control valve closes automatically. The performance of the spring mechanism shall meet the fire condition requirements specified in Clause 7.0.1 of this standard. When the requirements cannot be met, fire and heat insulation protection measures should be added. 2. For pneumatic actuators equipped with double-acting cylinders, fire and heat insulation measures should be implemented, and a spare air supply tank should be provided; the capacity of this spare tank should be sufficient to hold the amount of air required for one complete cycle from full open to full closed position. 3. Fire and heat insulation protection measures should be applied to electric actuators. 4. The fault-shutdown type electro-hydraulic actuator can be equipped with an accumulator fuse valve; in the event of a fire, the fuse valve opens and the accumulator releases energy to close the emergency isolation control valve. The actuator shall meet the fire condition requirements specified in Clause 7.0.1 of this standard. When the requirements cannot be met, fire and heat insulation protection measures should be added. 5. Fire and heat insulation protection measures should be applied to fault-latching electro-hydraulic actuators. The guidelines clearly specify in which scenarios fire shields need to be installed. By taking into account the specific conditions on site and the requirements of these guidelines, it is generally not a problem to choose to install fire shields.