When purchasing 3-way ball valves, you’ll come across several 3 way ball valve options such as body material, port size, and perhaps most importantly, flow paths/port types. Let’s take a look at some of the different types.

What is a 3-Way Ball Valve?

Before we get into different types, let’s talk about what a three-way valve is. A 3-way ball valve is a valve type with three ports, also known as openings. The connection between the ports has a metal ball with openings to control the media's flow direction.

Fluid or gas (media) flows through the valve, and there’s a mechanism to turn the ball, which directs flow from one place to another.

The 3-way valve is the most common type of multi-port ball valve. The ports are generally described as two outlet ports and one inlet, or vice versa, depending on the direction of the flow.

While 2-way ball valves are the most common overall, 3-way ball valves are the most widely used type of multi-port ball valve. They offer more flow control options than standard 2-way valves and are commonly used in applications requiring flow diversion, mixing, or redirection. The ports are generally described as two outlet ports and one inlet, or vice versa, depending on the direction of the flow.

How Does a 3-Way Ball Valve Work?

Depending on the shape of the valve, fluid or gas will enter through different sources and either co-mingle or be cut off from each other.

The valve works by turning a handle (mechanical valves) or activating an actuator (electric ball valves), which rotates the ball inside of the body of the valve. The rotating action aligns the channels with the inlets and outlets of the valve to direct flow.

What Do You Need 3-Way Ball Valves For?

One of the best parts of a 3-way valve is its versatility. They can perform a lot of different functions. These include:

• Switching flow from two locations
• Mixing a flow from two locations
• Stopping flow from one place but continuing it in another
• Flow diversion
• Completely stopping or shutting off the flow

What are the Different Types of 3-Way Ball Valves?

There are two different types of 3-Way valves to manage different flow paths – L-port and T-port. The ball valve is manufactured in a specific design to create either the L or T shape.

What’s an L-Port 3-Way Ball Valve?

L-port 3-way valves are also called diverting valves. There are two openings in an L-port, appearing in 90-degree angles that combine in the middle.

Turning the handle on an L-port will divert media from one place to another. It can also be used to switch pumps that have a standard outlet.

When using an L-port valve, the port in the middle would be the common one. L-port valves direct flow 90 degrees or shut it off.

Common Uses for an L-Port Valve

• To divert flow from one source to a secondary source
• Switching between one pump and a separate pump
• Diverting from free cooling to a chiller
• Diverting flow between two storage tanks

What’s a T-Port 3-Way Ball Valve?

A T-port valve can also send media from one place to another, but it can be moved so that the T lines up with the valve and all three ports get mixed.

Opposite flow direction is also possible, allowing one source to flow into two places at once.

T-port valves are designed for versatility. One of their primary functions is to allow flow between just two ports at a time, whether that’s through the left, right, or straight through. This makes them useful for applications where flow needs to be redirected without mixing, as well as for splitting or combining flows when all three ports are open.

Common Uses for a T-Port Valve

• Mixing two different fluid sources into one outlet
• Splitting flow from a single inlet to two outlets
• Running multiple tools from the same fluid source. For example, in a paint spraying system, a T-port valve can direct paint to a single spray gun in one position or supply two spray guns at the same time when all three ports are open. This allows for flexibility in operation without needing to swap hoses or use additional valves

How Do You Know If You Need a T-Port or L-Port Valve?

The easiest way to determine which valve you need is by considering how the flow needs to be controlled.

• L-port valves are typically used for diverting flow between two different outlets or for basic on/off control. Standard L-port valves do not allow flow to pass through all three ports at once, but some specialized versions can be configured for mixing, depending on how the ball is drilled or if handle stops are used.

• T-port valves are most commonly used for mixing or splitting flow. They allow fluid from two inlets to combine or a single inlet to split between two outlets. However, certain T-port valves can also be configured to shut off flow completely, depending on their internal drilling pattern.

If you need a setup where all flow can be stopped at the valve, be sure to check whether the specific T-port or L-port design you’re considering supports full shutoff.
Deciding between T-port or L-port valves comes down to need. It’s not a situation where one is better than the other; they are simply different.

How are the Pipes and Ports Lined Up?

The way a 3-way ball valve connects to your piping depends on whether it's an L-port or T-port configuration. The internal ball is drilled in either an "L" or "T" shape, determining how flow moves between the three ports when the valve is turned.

L-Port Valve: The center port is the common connection. Flow is directed at a 90-degree angle from one side port to the other, never allowing all three ports to be open at the same time. This setup is commonly used for diverting flow between two outlets or selecting between two inlets.

T-Port Valve: The T-shaped bore allows flow to move in multiple directions. Depending on the handle position, flow can go straight through, mix from two inlets into one outlet, or split from one inlet to two outlets. Some T-port valves can also be designed to shut off flow completely if drilled for that function.

Pressure Drops

FYI: Pressure drop can vary depending on the valve type and flow path. L-port valves require flow to make a 90-degree turn, which can introduce some resistance. T-port valves generally allow for straighter flow, but when all three ports are open, turbulence inside the valve can increase pressure drop. If your system relies on maintaining a specific flow rate or pressure level, it’s worth considering how different valve positions might impact performance. 

This is especially important to consider in high-flow systems, where excessive pressure loss can reduce efficiency and impact downstream performance. If maintaining a specific flow rate is critical, selecting the right valve configuration—or adding pressure compensation measures—can help mitigate these effects.

What are the Valve Functions?

L-port ball valves are generally used as a diverter service. If the desired effect is maximum flow in one direction, an L-port’s construction means the flow has to turn a corner regardless of the valve position.

A T-port ball valve means you can have a forward flow in one direction and diverted flow in the other. Think about flowing water through spray heads.

In one position, the water could spray, and in the other position, the divert port can drain the excess water from the heads.

Let’s say we’re connecting paint guns with a T-port ball valve. In position one, one paint gun could flow, but position two would allow for two paint guns at once, and all of the ports can be connected. This can’t be done with an L-port valve.

Quick Comparison Table of L-Port vs. T-Port 3-Way Ball Valves

Manual or Electric Valves?

Now that we've explored the different types of 3-way ball valves and their applications, let's discuss another important consideration: the actuation method. 3-way ball valves can be operated manually or electrically, each offering advantages depending on the specific needs of your system.

Whether to use manual or electric/motorized valves boils down to need. Does the application require constant fine-tuning or actions that must be manually handled by a person in the room?

Electric valves are more common in unmanned applications. They function the same way manual valves do, except motors handle opening, closing, dosing, and distribution.

They don’t even need to be operated in-house, although they can be if necessary. Many have remote operations from locations far away.

On the other hand, a motorized ball valve uses motors to rotate a ball with a hole for flow control. Generally, a motorized ball valve doesn’t need the power to hold its position the way a solenoid valve does. 

Glossary of Terms 

• Actuator: A device used to automatically operate a valve.  Actuators can be powered by electricity, pneumatics, or hydraulics
• Ball Valve: A valve that uses a rotating ball with a bore to control the flow of media
• Diverting Valve: A valve that directs flow from one path to another
• L-Port Valve: A 3-way ball valve with a ball that has an L-shaped bore, allowing flow to be diverted between two ports at a 90-degree angle
• Media: The fluid or gas that flows through a valve  
• Mixing Valve: A valve that combines the flow from two or more inlets into a single outlet
• Multi-Port Valve: A valve with more than two ports, such as a 3-way or 4-way valve
• Port: An opening in a valve body that allows media to enter or exit
• Shut-Off Valve: A valve that can completely stop the flow of media
• T-Port Valve: A 3-way ball valve with a ball that has a T-shaped bore, allowing flow to be mixed, split, or diverted between three ports
• 3-Way Ball Valve: A ball valve with three ports, offering versatility in flow control by allowing mixing, diverting, or isolating flows