| 1 | Rotary actuator function | A rotary actuator or motor symbol is represented by a circular operating element with directional triangles or other standardized internal indicators, depending on the function. | Converts hydraulic or pneumatic fluid power into rotary mechanical output. | Do not assume the symbol alone identifies vane, rack-and-pinion, helical, or other internal construction. | Specify construction type, rated torque, allowable rotation angle, speed range, and pressure range in the technical data. |
| 2 | Bidirectional rotation | Two opposed flow paths or two directional indications are used to show that the output can rotate in both directions. | Fluid supplied through one working port produces clockwise rotation; supply through the other produces counterclockwise rotation. | The circuit must identify which port produces each direction under the stated viewing convention. | Mark ports clearly, for example A and B, and define the viewing side used for clockwise and counterclockwise descriptions. |
| 3 | Single-direction rotation | A single directional indication is used when the actuator is intended to rotate in one powered direction, with return provided by another means. | Produces rotation in one direction by fluid power; spring, gravity, external load, or another actuator may provide the return action. | The return mechanism is not necessarily fully defined by the basic rotary symbol. | State the return method, return torque, fail position, and permitted installation orientation. |
| 4 | Limited-angle rotation | An arc, angular limitation, or supplementary angular notation may be placed with the actuator representation to indicate restricted rotation. | The output shaft rotates through a defined angle rather than continuously. | The basic symbol should not be read as a statement of a specific angle such as 90° or 180° unless that value is shown. | Add the nominal angle, adjustable range, end-stop tolerance, and cushioning information. |
| 5 | Continuous rotary motor | The motor symbol is used without a limited-angle specification when continuous rotation is intended. | Converts fluid power into continuous rotary motion. | Continuous rotation distinguishes the application from a quarter-turn or limited-angle actuator. | Specify displacement per revolution, rated speed, starting torque, continuous torque, and drain requirements where applicable. |
| 6 | Hydraulic operation | The actuator is connected to hydraulic lines and control valves using standardized line and port conventions. | Uses pressurized liquid, commonly hydraulic oil, to generate torque. | The symbol does not by itself define oil type, cleanliness level, pressure rating, or case-drain requirements. | List working pressure, peak pressure, fluid compatibility, filtration level, leakage limits, and temperature range. |
| 7 | Pneumatic operation | The rotary actuator is connected to pneumatic lines and directional control valves using the same graphical logic for fluid-power circuits. | Uses compressed air to produce rotary output. | The symbol does not establish air quality, lubrication method, operating pressure, or exhaust treatment. | State supply pressure, air preparation requirements, allowable leakage, speed-control method, and exhaust noise provisions. |
| 8 | Working ports | Ports are connected to the actuator by working lines and should be identified consistently in the circuit diagram. | Provides the fluid paths required to start, stop, reverse, or regulate rotation. | Port labels such as A, B, P, T, or equivalent designations must be interpreted together with the complete circuit. | Include port size, connection standard, flow direction, rated flow, and any dedicated drain or pilot port. |
| 9 | External pilot control | Pilot lines are shown separately from main working lines and connect to the relevant control element. | Uses a separate control pressure or signal to operate a valve or actuator function. | Pilot pressure is not necessarily the same as the main actuator pressure. | Define pilot pressure range, signal source, minimum control pressure, and response requirements. |
| 10 | Spring return or fail position | A spring or return element is added to the basic actuator representation when it is part of the functional circuit. | Returns the output toward a defined position when pressure or control input is removed. | The fail position depends on the actual mechanism, load, spring direction, and valve arrangement. | State normal position, fail position, spring torque, return time, and behavior under loss of supply. |
| 11 | Flow-control and speed regulation | Adjustable flow-control symbols are placed in the supply or return path according to the intended circuit function. | Controls actuator speed by regulating fluid flow. | Meter-in and meter-out arrangements can produce different behavior under overrunning loads. | Identify control method, adjustment range, reverse-flow check function, and stability requirements. |
| 12 | Cushioning and end-stop control | Cushioning or adjustable end-stop functions are represented by supplementary symbols or notes associated with the actuator. | Reduces impact or controls deceleration near the end of travel. | A basic actuator symbol does not guarantee shock absorption or adjustable stopping. | Specify cushion type, adjustment range, maximum inertia, stopping time, and allowable end-of-stroke energy. |
| 13 | Torque and load direction | Torque direction may be clarified by arrows, rotational notation, or supplementary circuit notes. | Defines the relationship between fluid input, shaft rotation, and external load torque. | Rated torque, breakaway torque, and dynamic torque are different performance values. | Provide torque-speed curves, load inertia, duty cycle, acceleration limits, and torsional shock conditions. |
| 14 | Symbol reading priority | Read the complete circuit from the actuator, through ports and lines, to the control and supply components. | Ensures that the actuator symbol is interpreted within the complete functional system. | A symbol should not be interpreted in isolation when directional valves, pilot lines, accumulators, or counterbalance valves are present. | Use consistent line types, port labels, flow arrows, component identification, and supplementary technical notes. |
| 15 | ISO 1219-1:2012 and GB/T 786.1 alignment | Both standards provide a common graphical-symbol approach for representing fluid-power components and circuit functions. | Supports clearer exchange of hydraulic and pneumatic circuit information across international and Chinese documentation. | Edition, language, national adoption status, and project-specific drafting rules should be verified before contract approval. | Cite the applicable edition in drawings and confirm symbol equivalence with the purchaser, designer, and inspection authority. |