Code of Federal Regulations

Title 14 - Aeronautics and Space
Volume: 1Date: 2023-01-01Original Date: 2023-01-01Title: Section 25.1125 - Exhaust heat exchangers.Context: Title 14 - Aeronautics and Space. CHAPTER I - FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION. SUBCHAPTER C - AIRCRAFT. PART 25 - AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES. Subpart E - Powerplant. - Exhaust System.
§ 25.1125 Exhaust heat exchangers. For reciprocating engine powered airplanes, the following apply: (a) Each exhaust heat exchanger must be constructed and installed to withstand each vibration, inertia, and other load to which it would be subjected in operation. In addition— (1) Each exchanger must be suitable for continued operation at high temperatures and resistant to corrosion from exhaust gases; (2) There must be means for the inspection of the critical parts of each exchanger; (3) Each exchanger must have cooling provisions wherever it is subject to contact with exhaust gases; and (4) No exhaust heat exchanger or muff may have any stagnant areas or liquid traps that would increase the probability of ignition of flammable fluids or vapors that might be present in case of the failure or malfunction of components carrying flammable fluids. (b) If an exhaust heat exchanger is used for heating ventilating air— (1) There must be a secondary heat exchanger between the primary exhaust gas heat exchanger and the ventilating air system; or
Code of Federal Regulations / Title 14 - Aeronautics and Space / Vol. 1 / 2023-01-01330
(2) Other means must be used to preclude the harmful contamination of the ventilating air. [Doc. No. 5066, 29 FR 18291, Dec. 24, 1964, as amended by Amdt. 25–38, 41 FR 55467, Dec. 20, 1976]