Flow Control

Flow Control

Flow control valves regulate the rate of fluid flow through a circuit, allowing the speed of cylinders, motors, and actuators to be set and maintained at the desired level. Without flow control, pneumatic and hydraulic actuators would move at maximum speed — uncontrolled movement that wastes energy, causes shock loads on machine structures, and creates safety risks in machinery. Properly configured flow control is the basis of controlled, repeatable machine motion. AIMS Industrial supplies flow control valves and regulators for pneumatic and hydraulic system applications.

Pneumatic Flow Control

In pneumatic systems, flow control valves are typically fitted in the cylinder supply or exhaust lines to regulate piston speed. Meter-in control (restricting the supply air to the cylinder) is used for resistive loads. Meter-out control (restricting the exhaust air from the cylinder) is the preferred arrangement for most applications — it provides smoother, more consistent speed control as the back-pressure stabilises the piston movement against load variations.

Inline flow control valves and push-in flow restrictors (fitting-mounted needle valves with integral push-in port) are the two most common forms. Push-in flow controls mount directly on the cylinder port for the most compact installation; inline valves are placed in the circuit where they are most accessible for adjustment during commissioning and maintenance.

Hydraulic Flow Control

Hydraulic flow control valves are more complex than pneumatic equivalents — they must handle higher pressures, higher flow rates, and the temperature and contamination challenges of hydraulic fluid. Compensated flow control valves maintain a constant output flow rate despite variations in inlet pressure and load — essential for applications where actuator speed must remain constant regardless of changing resistance. Uncompensated throttle valves are simpler and less expensive but do not maintain constant flow as pressure varies.

Needle Valves

Needle valves provide fine, precise flow adjustment through a tapered needle that gradually opens or closes a small orifice as the valve is turned. They are used for low-flow applications requiring very precise setting — instrument air supplies, lubrication metering, and chemical dosing. The fine thread gives good resolution of the flow setting over many turns of the adjustment stem. For flow control valve selection and sizing for your system, contact our team.

Selection and Sizing

Flow control valve selection requires matching the port size and flow coefficient (Cv or Kv) to the required flow rate and operating pressure. An undersized flow control valve restricts flow below the desired rate even at full open; an oversized valve has too little adjustment range for fine speed setting at the required flow. AIMS Industrial stocks pneumatic and hydraulic flow control valves in standard port sizes for Australian industrial and OEM equipment applications.