ISO 12584:2013 pdf download.Aerospace一Hydraulic fluid components – Expression of particulate contamination levels.
ISO 12584 defines the method of reporting and communicating the contamination (or cleanliness) level of components used in aerospace fluid systems.
It also presents a coding system which allows cleanliness data to be reported, both in a shortened manner and in a complete manner, when communicating for reporting contamination level measurement results and for specifying cleanliness requirements.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 11171, Hydraulic fluid power — Calibration of automatic particle counters for liquids
ISO 18413, Hydraulic fluid power — Cleanliness of parts and components — Inspection document and
principles related to contaminant collection, analysis and data reporting
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
component
general term to cover a part, a subassembly, or a part assembly used on an aerospace Iluid system
3.2
component cleanliness
condition of a component characterized by a level of particulate contamination
Note 1 to entry: Expression to be used preferably to set a specification.
3.3
component cleanliness code
ccc
alphanumeric expression of the particulate contamination level of a component or part for fluid circuits
3.4
particulate contamination
all undesirable particles which are in and on a component
Note 1 to entry: Expression to be used preferably to report measurements.
3.5
wetted surfaces
surface area of the component that is exposed to system liquid
EXAMPLE Hydraulic gear pump (see Figure 1).
Note I to entry: The wetted surface of a gear pump is the sum of the internal surfaces of the pump body (2 plates + 1 gear housing with 2 ports) and of the external surface of the two gear wheels. The example shown gives a simplified illustration and does not include all surfaces wetted by the hydraulic liquid.
3.6
wetted volume
volume of fluid contained in the component during normal operation
EXAMPLE Hydraulic gear pump (see Figure 2).
Note 1 to entry: The wetted volume of a gear pump is the volume of the gear housing minus the volume of the two
gears. The example shown gives a simplified illustration and does not include all of the volumes filled with the
hydraulic liquid.
4 Principle
The particulate contamination of a component is expressed by a level related to the number of particles in various size ranges and related to the wetted volume of the component. It is measured by counting particles after they have been extracted from the component by an appropriate extraction method (see ISO 18413).
5 Characteristics of the component
5.1 General
The fluid cleanliness code of ISO 11218 has served as a basis for the drawing up of the component cleanliness code.
ISO 12584 pdf download.