This part of ISO 15407 specifies the following requirements for a mounting interface for five-port pneumatic directional control valves, sizes 18 mm and 26 mm, without electrical connector, for use at a maximum rated pressure of 1,6 MPa [16 bar]: — dimensions and tolerances of the interface features; — port identification; — identification of the result of control-mechanism actuation. It is not applicable to the functional characteristics of interfaces. NOTE Requirements for mounting five-port pneumatic directional control valves of sizes 18 mm and 26 mm with optional electrical connector are given in ISO 15407-2.