The recommendations contained in this ARP are confined to the input and output characteristics of electrohydaulic flow-control servovalves. The information presented should be useful in standardizing the terminology@ the specification of physical and performance parameters@ and the test procedures used in conjunction with these components. The recommendations do not restrict nor attempt to define the internal design characteristics of servovalves. As such@ the material is equally applicable to servovalves having different internal functioning@ different ratings@ different physical size@ etc. in certain instances@ standards for valve design are recommended to increase component interchangeability@ as@ for example@ pigtail color-coding@ valve polarity@ mounting bolt and fluid port locations. The specifications contained herein should be adequate to describe electrohydraulic flow-control servovalves. Additional specifications may be necessary to define special requirements for specific control systems. Also@ specialized test procedures may be necessary to measure servovalve performance in these unusual specification areas. These consideration are beyond the scope of this recommended practice. PURPOSE - The recommended practice is intended as a guide to aid in the specification and testing of electrohydraulic flow-control servovalves.