On the LPG (Liquefied Petroleum Gas) outlet line from the bottom of the storage vessel (Horton sphere or mounded bullet), remote operated isolation valve (ROV) is provided for isolation of the facility in the case of emergency. This remote operated valve shall be fire-safe type conforming to API 607 or equivalent in order to protect the valve from external fire situation. In case of pneumatic operated ROVs, we would like to know whether the actuator system comprising of diaphragm & spring requires fire protection? If it is required, how the protection can be given? Is there any mechanical design requirement for the diaphragm/spring to protect the actuator from external fire case? What is the standard practice?