Should the make-up air control valve for the incinerator be open when air pressure is lost or closed?

Whether the make-up air control valve for the incinerator should operate in open mode or closed mode when air supply is lost depends on the specific application and the safety requirements of the incinerator. "\"Fail open\" and \"fail close\" refer to the default behavior of a control valve when it loses its control signal or actuation power source (such as air supply). Generally, when designing safety-related systems, the choice in a failure state is based on the safest location. For the make-up air control valve of the incinerator: – If too much make-up air is supplied, it may cause the temperature inside the furnace to rise excessively or lead to other safety issues; therefore, it might be necessary to design this valve as a fail-safe type, so that it closes in the event of a control failure, thereby reducing the amount of make-up air that enters the furnace and avoiding potential safety risks. - If insufficient supply of make-up air can lead to incomplete combustion, the emission of harmful gases, or increased carbon buildup in the furnace, it may be necessary to design it to open in the event of a loss of pressure, so that the valve opens when control fails and sufficient make-up air is supplied to maintain combustion quality. Therefore, when determining the air loss behavior of valves, it is necessary to analyze the safety risks of the incinerator under abnormal conditions, and make selections based on actual operating conditions, safety standards, and environmental protection requirements. Typically, such design decisions are determined during the initial design and risk assessment of the incinerator, and are detailed in the technical specifications and operation manuals. If there are any doubts or if it is necessary to verify the settings of a specific system, consult the relevant engineers or refer to the design documents of the incinerator. .