(R) Electrohydraulic Servovalves
|Publication Date:||1 April 2020|
This SAE Aerospace Recommended Practice (ARP) provides definitions and background information regarding the physical performance and testing of electrohydraulic flow control and pressure control servovalves. This ARP also provides extensive guidance for the preparation of procurement specifications and for functional testing.
NOTE: An example of a procurement specification is provided as Appendix A.
Field of Application
This ARP is applicable to electrohydraulic servovalves that are used in fluid power systems in all types of commercial and military flight vehicles.
Although the primary focus of this ARP is on four-way servovalves, three-way servovalves are discussed to a limited extent.
The requirements that are contained in ARP490 are confined to the interface definition and the input/output characteristics of electrohydraulic servovalves.
This ARP does not restrict or attempt to define the internal characteristics of servovalves. As such, the recommendations are equally applicable to valves having different internal functioning, different ratings, different physical size, and valves used with different fluids. In certain instances, standards for valve design are recommended for the purpose of interchangeability; for example, as valve polarity, mounting bolt, and fluid port locations.
The servovalve will be used to control the actuators in the flight control subsystem of an aerodynamic surface.