---
kind: "section"
citation: "14 C.F.R. § 121.231"
title: "14"
number: "121.231"
heading: "Fuel system lines and fittings."
url: "https://uscodex.org/cfr/14/121.231"
---

# §121.231. Fuel system lines and fittings.

- (a) Fuel lines must be installed and supported so as to prevent excessive vibration and so as to be adequate to withstand loads due to fuel pressure and accelerated flight conditions.
- (b) Lines connected to components of the airplanes between which there may be relative motion must incorporate provisions for flexibility.
- (c) Flexible connections in lines that may be under pressure and subject to axial loading must use flexible hose assemblies rather than hose clamp connections.
- (d) Flexible hose must be of an acceptable type or proven suitable for the particular application.

## Notes

### Source

Source: Docket 6258, 29 FR 19202, Dec. 31, 1964, unless otherwise noted.

### Authority

Authority: 49 U.S.C. 106(f), 40103, 40113, 40119, 41706, 42301 preceding note added by Pub. L. 112-95, sec. 412, 126 Stat. 89, 44101, 44701-44702, 44705, 44709-44711, 44713, 44716-44717, 44722, 44729, 44732; 46105; Pub. L. 111-216, 124 Stat. 2348 (49 U.S.C. 44701 note); Pub. L. 112-95, 126 Stat. 62 (49 U.S.C. 44732 note); Pub. L. 115-254, 132 Stat. 3186 (49 U.S.C. 44701 note).