(2)
The region surrounding the heater, if the heater fuel system has .ttings that, if they leaked, would allow fuel or vapors to enter this region.
(3) Thepartofthe ventilating airpassagethat surroundsthe combustion chamber. However, no .re extinguishment is required in cabin ventilating air passages.
(b)
Ventilating air ducts. Each ventilating air duct passing through any .re zone must be .reproof. In addition–
(1)
Unless isolation is provided by .reproof valves or by equally e.ective means, the ventilating air duct downstream of each heater must be .reproof for a distance great enough to ensure that any .re originating in the heater can be containedintheduct; and
(2)
Each part of any ventilating duct passing through any region having a .am-mable .uid system must be constructed or isolated from that system so that the malfunctioning of any component of that system cannot introduce .am-mable .uids or vapors into the ventilating airstream.
(c)
Combustion air ducts. Each combustion air duct must be .reproof for a distance great enough to prevent damage from back.ring or reverse .ame propagation. In addition–
(1)
No combustion air duct may have a common opening with the ventilating airstream unless .ames from back.res or reverse burning cannot enter the ventilating airstream under any operating condition, including reverse .ow or malfunctioning of the heater or its associated components; and
(2)
No combustion air duct may restrict the prompt relief of any back.re that, if so restricted, could cause heater failure.
(d)
Heater controls;general. Provision mustbe made toprevent the hazardous accumu-lation of water orice on orin anyheater control component, control system tubing, or safety control.
(e)
Heater safety controls.For each combustionheater there mustbe thefollowing safety control means :
(1)
Means independent of the components provided for the normal continuous control of air temperature, air.ow, and fuel .ow must be provided, for each heater, to automatically shut o. the ignition and fuel supply to that heater at a point remote from that heater when any of the following occurs :
(i)
The heat exchanger temperature exceeds safe limits.
(ii)
The ventilating air temperature exceeds safe limits.
(iii) The combustion air.ow becomes inadequate for safe operation.
(iv) The ventilating air.ow becomes inadequate for safe operation.
(2)
[The means of complying with subparagraph (1) of this paragraph for any individual heater must–
(i)
Beindependentof components serving any otherheater whoseheat output is essential for safe operation; and
(ii)
Keep the heater o. until restarted by the crew.]
(3)
There must be means to warn the crew when any heater whose heat output is essentialfor safe operationhasbeen shut o.by the automatic meansprescri-bedin subparagraph(1) of thisparagraph.
(f)
Air intakes. Each combustion and ventilating air intake must be located so that no .ammable .uids or vapors can enter the heater system under any operating condition–
′
Elodie Roux. Septembre 2003
Subpart D : Design and Construction
(1)
During normal operation; or
(2)
As a result of the malfunctioning of any other component.
(g)
[Heater exhaust. Heater exhaust systems must meet the provisions of Secs. 25.1121 and 25.1123. In addition, there must be provisions in the design of the heater exhaust systemto safely expeltheproducts of combustiontopreventthe occurrence of–]
(1)
Fuel leakage from the exhaust to surrounding compartments;
(2)
Exhaustgasimpingement on surrounding equipment or structure;
(3)
Ignitionof .ammable .uidsby theexhaust,if theexhaustisinacompartment containing .ammable .uidlines; and
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址：FAA规章 美国联邦航空规章 Federal Aviation Regulations 3(106)
