A Complete Guide to 3 Way Valve

There would be almost no industrial processes without valves. These devices are responsible for the regulation, diversion, and the control of the flow of liquid or gasses. Valves are of different types depending on the structure, operating mechanism, power source, and application. 

Defined by its number of ports, the 3-way valve is a type commonly used in industrial applications. Due to its inevitability in the industrial world, it is therefore important to take a look into what this device mean, the types, how it works, and other salient factors.

WHAT IS A 3-WAY VALVE?

A 3-way valve is an industrial valve with a steady flow rate used for diversion or mixture of applications. It’s also known as a multiport valve because of its three openings which can be connected to tubing for the flow of liquid or gas. These openings in the 3-way valve types either come as two inlets and one outlet, or one inlet and two outlets. This is determined by the connection application.

The rate of flow in the different valves remains steady despite being a multiport valve. A constant flow rate is maintained in any application where the valve is used even though the liquid or gas will be split into two separate openings.

The structure of this valve allows one open orifice with the other one closed or vice versa. This makes it easy for the device to be used for pressure application as an option to exhaust pressure from a valve actuator or a single-acting cylinder. 3-way valves are normally opened, closed, or universal.

This mechanism devised by the valve allows it to provide a convenient way of moving the flow of liquid or gas from one point to another. 

Furthermore, the mechanism of the 3-way valve also makes it inexpensive, allowing its users to save money by eliminating the use of conventional gate valves and bypass appliances often used in steam generating plants. Not only does it eliminate conventional 3-way globe valves, it also shut-off control in one single valve body and provides flow direction. 

3-WAY VALVE SYMBOL

A 3 way ball valve symbol is a modification of the 2 way ball valve symbol, which consists of two triangles facing each other with a ball at the center. 

In the 3-way ball valve symbol, three triangles are pointing towards each other with a ball at the center. This goes to show that this valve can be generic when it doesn’t indicate the type of 3-way ball valve present or it can be a symbol with a modifier when it shows the exact type of 3-way ball valve present in the piping. 

The symbol is of two types: generic symbol, and the symbol with a modifier.

• Generic valve symbols indicate the presence of a valve in the piping and instrumentation diagram. That is as far as it goes. The generic symbols do not indicate the type of valve present. Rather, they show the presence of a valve in the diagram which is to be used in the pipeline. 
• The symbol with a modifier, just as the name implies, goes beyond just indicating the presence of a valve in the piping and instrumentation diagram. It goes as far as pointing out the exact type of valve present in the diagram which is to be used in the pipeline.  

TYPES OF 3-WAY BALL VALVE

The 3-way ball valve, like other ball valves in the multiport valve family, has its types. It is therefore important to know them.

There are two major types of three-way valves: The T-port valve and the L-port valve. They are named after their shape, and their usages are dependent on the function you want them to perform. The T and L shapes refer to the opening in the middle of the 3-way ball valves. 

• T-PORT 3-WAY BALL VALVE

The T-port valve is thus named because it has a T shape. It is also called the 180-degree ball. This ball valve type can merge two inlet flows into one outlet port. Depending on the system requirements, it can also split one inlet into two outlet flows.

The T-port 3 way valves are commonly used to split the flow of gas and liquids. Based on the permissible range of the handle motion and the system’s requirements, the T-port 3 way ball valve can be used in splitting or mixing flow, diverting flow, and enabling a straight flow.

In addition, the T-port valve can not only flexibly control the merging or diverging of the medium in the pipeline, but also make the three channels communicate with each other.

General Applications For 3-Way T Port Valve

The 3-way ball valve T port can be used to connect the openings in a pipeline, allowing for different inlet and outlet flow patterns. Generally, the 3-way ball valve T-port valve is preferred in most cases as it allows for multidimensional flow patterns, unlike the L-port valve which seems to be non-dimensional. 

The T-port valve ensures a straight flow through the valve when it is in one position with little or no loss of pressure and diverts to another direction when the position is changed. 

The 3-way ball valve T-port valve can have up to two paint sprayers simultaneously alongside the three ports connected. 

• L-PORT 3-WAY BALL VALVE

The L-port 3 way valve is also called the 90 degrees ball.  This ball valve allows the flow of liquid or gas from one inlet into one of the two separate outlets. Its mechanism in the L port 3 way ball valve gave it the name “diverter valve”. Unlike the T-port valve, the L-port 3 way ball valve diverts or coordinates flow in one direction.

It can restart, restrict or shut off the flow, unlike the T-port valve. The handle of the valve has its ranges in 90 degrees i.e it’s calibrated in 90 degrees, 180 degrees and so on until it gets to 360 degrees. However, whatever angle it takes, the direction is in one way. 

The L-port ball valve is quite useful in applications where more than one source is used in drawing liquid or gasses into another pipe. 

There’s the double L-port ball valve which is a 4-way valve used to confirm flow with 4 pipes connected to a valve. There are also flanged valves which have their ends flanged in order to connect to any pipe either with a bolt or by welding. 

General Applications For L-Port 3-Way Ball Valve

The L-port way valve is used in applications that need a diverter. This is because it can divert flow from one primary source to another.  This valve also allows simple switching between pumps, i.e, switching liquid or gas from one pump to another. 

In addition, the L-port 3-way valve allows diverting flow from and between storage tanks as well as from cooling to chilling. 

The 3-way T-port valve and the L-port valve are the main categories of the 3-way ball valve, which also entails the following: 

• Generally, an open valve allows flow from two ports, while sealing the other port known as the stop orifice. The open valve allows flow from one orifice (known as the body orifice) through the valve and out through the other orifice (known as the cavity port).
  
  This can happen vice versa meaning that another orifice can be sealed and the other two becomes the inlet and outlet depending on the system requirements. The open valve always has one opening. 

• Usually closed valves operate like the open valve. In the system of a usually closed valve, one orifice (the body orifice) is sealed off leaving the other two orifices (the cavity port and stop port) open. This allows flow from the cavity port through the valve and out the stop port. 
  
  The system requirements change the inlet and outlet just like in the open valve (the stop orifice can be sealed off allowing flow from the body orifice through the valve and out of the stop orifice). The closed valve always has one orifice closed.

• The directional control valve operates a little bit differently from the generally open and closed valve. The directional control valve allows for two ports of flow. When the stop orifice is sealed off, the body orifice is responsible for directing the line of flow through the body of the valve.

Several industrial valve manufacturers believe that the 3-way valve is one of the most used valves as it gives room for different system requirements, allowing different styles of flow in a pipeline or in whatever system it is applied. 

ADVANTAGES OF THE 3-WAY BALL VALVE 

It is important to note that the design of the valve determines the style and flow pattern in a system. The advantages of the 3-way ball valve cannot be overemphasized as it does not just fit into any system but can perform more than one function.

Below are some of the various advantages of the 3-way ball valve.

• Has a simple structure with low volume.

• Is the most cost-effective among other types of valves. This is because it can perform more than one function depending on the system requirements.

• Has low media resistance.

• Can mix up two different media types given that there are three ports in the valve.

• Can divert the direction of flow from one point to another considering it has reliable sealing.

• Can split the flow of any type of media into two different directions.

• Can stop the flow of one media in a particular direction and allow another media to flow in that same direction.

• Has a wide range of applications – it can be used across different system requirements which could be low pressure or even high vacuum.
• Can clean itself by eliminating erosion to the seat caused by high speed fluid and washing away accumulated things on the sealing face. 
• Can operate conveniently with the valve opening or closing rapidly. It can only be open or closed completely by turning 90 degrees.
• Has the ball and sealing face of the seat separated from the medium when the valve is completely opened or closed.

3-WAY VALVE FUNCTION

As stated earlier, 3-way valve function is largely dependent on the system requirements. Since it can be used for a wide range of applications, the functions will be dependent on what is required of the valve in the system where it is applied. Some of such functions include:

• Shutting off the flow of liquid or gas (media) in a piping system.
• Opening the flow of liquid or gas in a piping system.
• Mixing of liquid or gas from two different pipes.
• Diverting flow of liquid or gas in the valve.
• Mixing of two different media in a piping system.

These and more are determined by the system requirements, thus the design of different types of 3-way ball valves.

HOW DOES A 3-WAY BALL VALVE WORK? 

Just like multi-port ball valves, the 3-way ball valve provides a control for piping applications. Its mechanism differs a little bit according to the type and this is because it works by turning a handle or by turning on an actuator (this is for 3-way electric ball valves). 

This action rotates the ball inside the multiport valve causing the channels to align with the inlet and outlet ports giving direction to the flow of liquid or gas. The handles have a range of motion and the range of motion differs according to the type.

Quickly, let’s explore the mechanism in the L-port 3-way valve and the T-port 3-way valve.

The mechanism in the L-port 3-way valve allows the direction of flow of media to be changed by turning a handle to 90 degrees. This means that every time the handle is turned 90 degrees, the direction changes because one port is sealed and then another port opens up. The valve’s mechanism doesn’t allow the three ports to be open at the same time.

The mechanism in the T-port valve or the 180 degrees valve allows the three ports to be open simultaneously. The T-port valve allows media from two different ports to be mixed in the body of the valve and exit through the other opening. The T-port shape allows media to flow in through two ports and out through one and vice versa. 

The bottom line is the mechanism of the 3-way ball valve is not fixed, but can change according to the type of valve used and the system requirements.

2-WAY VS 3-WAY VALVE（THE DIFFERENCE)

Generally, valves or ball valves play very important roles in industrial processes. The 3-way ball valve is not the only existing ball valve. There are several valves existent, but the 3-way ball valve because of its flexibility seems the most common. 

The question is, what is the difference between the 2 way ball valve and the 3 way ball valve? Is it just the name that’s different or are there characteristics that make them different?

• The first very notable difference between these two types of ball valves is that the 2-way ball valve has just two ports, and openings (an inlet and an outlet). It is quite straightforward. On the other hand,  the 3-way ball valve has three ports and any of the three ports can be used as an inlet, inlets or outlet depending on the system requirements. 
• The 2-way ball valve is restricted as its two ports allow only a single straight flow of media through the valve (i.e from one end to another without diverting or mixing the media).
  
  On the other hand, the 3-way ball valve with its three ports is more suitable for rather complex processes that cannot be accomplished by the 2-way valve. Also, the 3-way ball valve operation allows diversion of the direction of media flow and also allows mixing of media in the valve.

• The 2-way ball valve is majorly used as a shut-off valve otherwise known as an isolation valve while the 3-way ball valve is used for both controlling the direction of flow of media, mixing of media and shutting off of the valve. 
• The 2 way ball valves are more efficient when it comes to the regulation of temperature and pressure of the flow of media in and out of the valve. 
• The 3-way ball valve has a more constant flow rate than the 2 way ball valve because once the handle is turned and the channels are aligned with the ports of the valve, the flow of media in and out of the valve is undisturbed. On the other hand, the flow rate in a  2-way ball valve fluctuates due to the opening and closing of the valve. The 3-way ball valve is to be used with a system that has a constant flow of water.
• The use of 2-way valves will require extra accessories in systems where mixing and diversion of fluids will be required. In cases like this, the 3 way ball valve will be cost-effective as it can perform multiple functions in itself (mix different media and also divert the direction of the flow of media).
• While the 3-way ball valve is cost-effective, the 2-way ball valve is cheaper to buy and install. In most cases, some industries choose the 2-way ball valve especially when it comes to regulating certain parameters.
• The 3-way valve alters the direction of fluid from inside of the cooling coil to the outside and is efficient in applications where secondary pumps with variable speed are used while the 2-way valve, having only two positions (on/off), is deployed  in the cases  where the constant speed pumps are used.

The differences between the 2-way ball valve and the 3-way ball valve are majorly hinged on the number of ports they possess. These ports determine the mechanism of the functions they perform when attached to piping or tubing for liquid or gas. 

WHY ARE HANDLES SO IMPORTANT FOR THREE-WAY BALL VALVES？

Given how flexible a 3-way valve is, one would think that handles are of less use for the valve. The handles though are significantly more important than we can imagine. The 3 way ball valve is powered by a handle. The handle is more or less the deciding factor of how efficient the 3 way valve works.

Generally, all ball valves come with handles which keep them from exceeding a certain degree of turn. For the this ball valve, handles are important because of the number of ports of the valve. The handle provides control through its limited range of motion.

The range of motion specifies the amount of liquid or gas that is to be mixed or diverted. In essence, the flow pattern in a three-way is determined by the handle.

Practically without the handles on a 3-way ball valve, there will be no control of the amount of media that will pass through the valve. It eventually will end up in a mess as an excessive amount of media can go through the valve and can eventually cause a breakdown in the piping system.

CONCLUSION

3-way ball valves are one of the most important types of ball valves; they serve diverse roles in different systems in industrial processes. They play significant roles at different points in a pipe and tube system for liquid or gas flow. 

Proven to be cost-effective, its mechanism is a good show of flexibility as it fits into a wide range of system requirements allowing the valve to perform different functions in different systems at a time. For industrial processes and their complexities, the 3-way ball valve will be the best pick because of all its capabilities. Contact a professional valve factory to know more about it.