Difference Between 2-way, 3-way, and 4-way Valves

The main difference between 2-way, 3-way, and 4-way valves lies in the number of ports and their functionality, which affects how they control the flow of fluids (liquids or gases).  Here’s a breakdown of each type:

2-Way Valve

Ports  -  Has two ports (an inlet and an outlet).
Function:  -  Allows fluid to flow in one direction or stops it completely. It's essentially an on/off valve for controlling flow.
Application:  -  Commonly used for simple shutoff or isolation applications, such as turning water or gas flow on and off.

3-Way Valve

Ports  -  Has three ports.
Function  -  Directs fluid flow between two different pathways, allowing for mixing, diverting, or selecting flows.

• Mixing Valve  -  Combines fluids from two inlets into one outlet.
• Diverting Valve  -  Splits flow from one inlet into two different outlets.

Application  -  Useful in heating and cooling systems for controlling temperatures, switching between flow paths, or selecting sources.

4-Way Valve

Ports  -  Has four ports.
Function  -  Typically used to reverse the direction of fluid flow or to switch between different circuits. Common in systems that need to alternate flows.
Application  -  Often used in hydraulic systems, HVAC systems (like reversing the flow in heat pumps), and some pneumatic applications to change the direction of actuator movement or switch between high- and low-pressure paths.

Each type of valve serves a unique purpose in directing fluid flow, making them suited to specific applications based on the number of pathways and control requirements.