Types of Air Piloted Valves and Their Specifications

Air piloted valves control compressed air, inert gas and liquid using pneumatic pressure as an actuator. They use the force of compressed air to shift a piston or diaphragm into an open or closed position depending on the application.

Air operated valves are available in 2-, 3- and 4-way designs and can perform various functions, including flow control and pressure regulation.

Small 2- and 3-Way Air Piloted Valves

Two-way air piloted valves have two positions and with normally closed or normally open functions. When actuated by compressed air, the valve shifts to its second position, either to open fluid flow or to close fluid flow.

A valve with three ports offers additional downstream exhaust or drain capability. The first port connects the supply source to the valve, the second port connects downstream to the controlled work to be performed and the third port serves as a downstream exhaust or drain. With two positions, the common second port opens to either the first or third port upon actuation.


Humphrey’s compact, diaphragm-poppet 2- and 3-way air piloted valves feature a rugged design that cannot stick and will not leak. Our small valves can optimize flow capacity and handle high-pressure applications that involve air, vacuum, mild gas and mild liquid.

Our valve specifications include:

  • Number of ports: 2 or 3
  • High flow capacity: up to 75 ft³min
  • Valve function: single air pilot operated, normally open or normally closed
  • Port size: 1/8 and 1/4 NPSF
  • Pressure range: 0-125 psi

Large 2- and 3-Way Air Piloted Valves

Our large 2- and 3-way air operated valves are dependable for applications requiring high flow capacity. Available in diaphragm-poppet and piston-poppet designs, these three port valves can feature multi-purpose functionality and perform as efficient 4-way functions when used in pairs near the work.


Humphrey’s large 2- and 3-way air piloted valves offer the same durable design as our smaller valves and can withstand operation in harsh, dirty and wet environments. These air piloted valves can handle air, inert gas and mild liquids.

Valve specifications include:

  • Number of ports: 2 or 3
  • Flow capacity: up to 220 ft³min
  • Valve functions: single pilot, normally closed or open, diverter, selector
  • Port size: 1/2 and 3/4 NPT
  • Pressure range: 10-125 psi

Small 4-Way Air Piloted Valves

This type of air operated valve is ideal for applications that require pressure management and directional control. In a 4-way valve, one port is connected to the supply source, two ports are connected to the cylinder or actuator, and the fourth acts as an exhaust pathway. These valves have two (or sometimes three) positions. In one position, the supply port is open to one cylinder port while the second cylinder port is open to the exhaust port. When actuated to the second position, the supply and exhaust ports switch, opening to other cylinder ports.


Humphrey’s small 4-way air operated valves can provide single or double air piloted function. The compact design allows close proximity mounting and supports fast cycling and quick exhaust.

Valve specifications include:

  • Number of ports: 4 or 5
  • High flow capacity: up to 75 ft³min
  • Valve functions: Single air pilot – spring return, or double air pilot – detented
  • Port size: 1/4 NPSF
  • Pressure range: 0-125 psi

Large 4-Way Air Piloted Valves

Four-way valves are the most common type of valves for pneumatic automation systems. They can thrust forward and reverse the motion of air motors or air cylinders. Large air piloted valves can be mounted near large actuators for high performance and safety purposes.


Our large 4-way air piloted valves feature a high-flow poppet design and can provide consistent function, even in poor air conditions.

Valve specifications include:

  • Number of ports: 4
  • High flow capacity: up to 170 ft³min
  • Valve function: 4-way single air pilot, spring return
  • Port size: 1/2 NPT
  • Pressure range: 0-125 psi

Which Type of Air Piloted Valve is Right for Me?

Selecting the proper valve for your application depends on operational requirements, media, valve size and industry specifications.

Here are some valve considerations to help narrow your search:

  • Temperature rating, media and surroundings
  • Ambient environment: clean, dirty, dusty, wet, dry
  • Media pressure range
  • Flow rate, fill and exhaust times for cylinder or actuator
  • Installation
  • Maintenance

The expert team at Humphrey Products can help determine what type of air piloted valve can optimize your application. Review our catalog of air operated valves and contact us if you require further assistance.

Small silver & bronze 2- and 3-way air piloted valves