CS-25 L25 Strength Value

Element of System Proof Ultimate Remarks Rigid pipes and ducts 1·5 PW Couplings 1·5 PW Flexible hoses 2·0 PW Return line elements – Components other than pipes, 1·5 PW couplings, ducts or pressure vessels Pressure vessels fabricated from metallic materials. (For non-metallic materials see CS 25.1436(b)(7)) 3·0 PW 3·0 PW 4·0 PW 1·5 Pf Pf The maximum pressure applied during failure conditions. 2·0 PW Pressure vessels connected to a 3·0 PL or 4·0 PL or The lower values are conditional upon line source of pressure 1·5 PL 2·0 PL justification by a fatigue endurance test from which a permissible fatigue life is declared, and upon the ultimate load test being made on the test specimen used for the fatigue life test. Pressure vessels not connected to 2·5 PL or 3·0 PL or The lower values are conditional upon a line source of pressure, e.g. 1·5 PL emergency vessels inflated from a ground source 2·0 PL justification by a life endurance test of a suitably factored permissible number of inflation/deflation cycles, including temperature fluctuation results in a significant pressure variation, and upon the ultimate load test being made on the test specimen used for the life endurance test. For all pressure vessels: (1) The minimum acceptable conditions for storage, handling and inspection are to be defined in the appropriate manual. See CS 25.1529. (2) The proof factor is to be sustained for at least three minutes. (3) The ultimate factor is to be sustained for at least one minute. The factor having been achieved, the pressure vessel may be isolated from the pressure source for the remaining portion of the test period.