Comparing Solenoid and Proportional Solenoid Valves

Solenoid and proportional solenoid valves differ in their capabilities for managing flow control, volume and pressure. Both have unique advantages that are suitable for different industries and applications.

What is a Solenoid Valve?

A solenoid valve controls media flow by fully opening or closing the flow path upon actuation from electromagnetic energy. The device contains a coil that creates a magnetic field when it receives an electrical current from the valve driver. The magnetic field attracts the plunger, overcoming the spring mechanism to open or close a flow path.

Solenoid valves are diverse in their composition, design and application. They can be equipped with 2, 3, 4 or 5 ports and controlled directly by the solenoid or via an internal air pilot. Solenoid valves offer excellent directional control for most applications and fast response times for rapid cycling.

Solenoid Valve Selection and Specs

Solenoid valves are available in miniature, small and large sizes.

Miniature solenoid valve specs:

  • Number of ports: Typically 2 or 3
  • Port size: Typically 10-32 unf or smaller
  • Flow coefficient: 0.01-0.10 Cv

Small solenoid valve specs:

  • Number of ports: Typically 2, 3, 4 or 5
  • Port size: Typically 1/8 or 1/4 Pipe
  • Flow coefficient: 0.10-1.0 Cv

Large solenoid valve specs:

  • Number of ports: Typically 2, 3, 4 or 5
  • Port size: Typically 3/8, 1/2 or 3/4 Pipe
  • Flow coefficient: >1.0 Cv

Common Uses for Solenoid Valves

Humphrey Products offers direct-acting and pilot-operated solenoid valves that are suitable for various industries.

Solenoid valves can be used in:

  • Factory automation
  • Mobile equipment
  • Material handling
  • Biomedical equipment
  • Assembly and packaging equipment
  • Processing equipment

What is a Proportional Solenoid Valve?

A proportional solenoid valve regulates flow in proportion to the amount of electric current applied to its solenoid operator. It allows you to precisely adjust and control the flow rate of a pressurized gas or liquid media up to its maximum opening.

The solenoid generates an electromagnetic field that attracts the plunger, opening the valve only in proportion to the input current applied to the coil. A proportional solenoid valve allows flexibility in applications requiring precise delivery of volume and pressure.

They can be specified for air, gas or fluid and function as a pressure relief or flow controller in a closed-loop system.

Proportional Solenoid Valve Components and Specs

Proportional solenoid valves include the coil, core, special spring and plunger. This type of solenoid valve typically includes a down-stream feedback mechanism that monitors the down-stream behavior and sends information back to the controller and the solenoid (closed-loop).

Humphrey’s proportional solenoid valves feature low hysteresis, cycle repeatability and precision control.

Small proportional solenoid valve specs:

  • Number of ports: 2
  • Maximum operating current: 400 mA
  • Flow: <250 LPM maximum capacity

Large proportional solenoid valve specs:

  • Number of ports: 2
  • Maximum operating current: 600 mA
  • Flow: >250 LPM maximum capacity

Common Uses for Proportional Solenoid Valves

Proportional solenoid valves provide exceptional flow control and extreme precision. They are used for ongoing dynamic control applications (closed loop), for pre-determined flow changes in a single cycle and for selectable flow control from cycle to cycle.

These applications are used as in:

  • Industrial Controls
  • Factory Automation
  • Analytical Instruments
  • Lab Equipment
  • Chemical Processing
  • Medical Gas Delivery
  • Pressure Regulation

Solenoid and Proportional Solenoid Valves from Humphrey Products

Find the right solenoid or proportional solenoid valve to optimize your application at Humphrey Products. We’ve put decades of research into our products and offer a wide variety of customizable designs. Contact our expert team to learn more about our products and request a quote.