Proportional Solenoid Valves for Various Flow Applications

Some pneumatic valve applications require more precise flow control than what’s possible with standard on/off solenoid valves. Proportional solenoid valves offer a solution.

They open to flow capacity in response to the amount of electrical current applied to the solenoid, enabling fine flow

control adjustments, smooth transitions and gradual pressure increases or decreases.

Humphrey Products’ ProControl™ PV3, PV10 and PC30 models accept a wide range of input signal types, supporting broad flow capacity across many applications. The following sections outline how they optimize specific equipment and systems.

Small 2-Port Proportional Solenoid Valves

Miniature 2-Port Proportional Solenoid Valves

Medical and Life Science Equipment

Precision media flow control is critical when patient safety is on the line. Proportional solenoid valves help meet that standard across several types of medical equipment.

Respiratory and anesthesia equipment: Ventilators, anesthesia machines and CPAP/BiPAP devices rely on proportional solenoid valves to precisely control gas flow. They provide minute adjustments to airflow to ensure comfortable media delivery to the patient.

Fluid delivery: Infusion pumps often use pneumatically actuated valves that meter fluid flow and keep the path sterile. That’s essential for accurate medication dosing during IV therapy. Proportional valves allow medical equipment pumps to deliver media at a prescribed rate without abrupt changes that could be dangerous to patients.

Dialysis: Because dialysis equipment withdraws blood from the patient and returns it, the valves within the machine must carefully control the flow of media. Proportional valves can be used to dispense sterilizing agents between treatments, too.

Modern anesthesia workstation with a digital monitor

Food, Chemical and Pharmaceutical Processing

Precise, repeatable flow control matters just as much in processing environments as it does in medical settings. Proportional solenoid valves support several stages of food, chemical and pharmaceutical operations, typically by managing the compressed air or inert gas that drives the process rather than the end product.

Gas dosing and packaging: Proportional solenoid valves meter precise volumes of nitrogen and other inert gases used in modified atmosphere and pharmaceutical packaging for tablets, capsules and other dosage forms. That process preserves shelf life and product integrity from batch to batch.

Pneumatic actuation for filling equipment: In bottling and dosing lines, these valves regulate the compressed air signal that drives diaphragm- or piston-actuated filling. That gives pneumatic equipment the fine, repeatable control needed for consistent dose volumes without the proportional valve contacting the product.

Purge and drying cycles: Between production cycles, proportional solenoid valves control the compressed air or inert gas used to purge lines and dry equipment. They can also regulate the air that actuates the pneumatic valves controlling cleaning-fluid flow.

Worker in a white cleanroom suit and hairnet using a touchscreen control panel

Industrial Automation

Proportional solenoid valves give automated industrial systems the fine control necessary for consistent, repeatable motion. Common applications include:

Pick-and-place systems: Proportional valves modulate cylinder speed and force, so robotic arms can pick up delicate parts of varying weight without dropping or crushing them. They’re a crucial component in sorting processes where disruption in control can lead to costly downtime and adjustments.

Assembly line cylinders: These valves control the acceleration and deceleration of pneumatic cylinders, producing smoother motion and less mechanical shock across repeated cycles.

Packaging equipment: Proportional valves fine-tune the air pressure driving seal, cut and fold operations. That keeps packaging quality consistent at high line speeds across multiple cycles without lag.

Test and inspection equipment: Precise, repeatable air pressure control allows test stands and inspection rigs to apply calibrated force during quality checks.

Machine tool clamping: Proportional valves regulate the clamping pressure applied to machined components, maintaining a secure hold without damaging the part.

Close-up of an automated robotic pick-and-place arm

Let the Experts Help You Find the Right Valve

Choosing the right proportional solenoid valve depends on your application’s specific flow, pressure and signal requirements. Humphrey Products’ engineering team can help you evaluate your system and select the right ProControl™ model to keep your equipment running precisely and reliably.