This part of ISO 10771 specifies a method of fatigue testing the pressure-containing envelopes of components used in hydraulic fluid power systems under sustained steady cyclic internal pressure loads. This part of ISO 10771 is only applicable to component pressure-containing envelopes that: - are manufactured from metals; - are operated at temperatures that exclude creep and low-temperature embrittlement; - are only subjected to pressure-induced stresses; - are not subjected to loss of strength due to corrosion or other chemical action; - may include gaskets, seals and other non-metallic components; however, these are not considered part of the pressure-containing envelope being tested, (see note 3 in 5.5). This part of ISO 10771 does not apply to piping as defined in ISO 4413 (i.e. connectors, hose, tubing, pipe). See ISO 8434-5, ISO 6803 and ISO 6605 for methods of fatigue testing of piping devices. This part of ISO 10771 establishes a general test method that is applicable for many hydraulic fluid power components, but additional requirements or more specific methods that may be required for particular components are contained in the annexes or other standards.