Understand what valvesĀ are, the types of valvesĀ that exist, and their uses within piping. In this guide, learn specifically about ball valves, gate valves, globe valves, butterfly valves, check valves, pressureĀ relief valves, and pressure regulatingĀ valves.
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What Is A Valve?

A valveĀ is a device used to decrease or stop theĀ flowĀ of a fluidĀ in piping. It is a type of pipeĀ fitting that controlsĀ the flowĀ inside a pipeline.
ValvesĀ can be operatedĀ manually by turning the handle of the valve, or automatically by using a pressureĀ difference and an actuator. An actuatorĀ is a device that automatically controlsĀ the valveĀ on or off.Ā
Types of Valves
There are two categories of valvesĀ for piping: shut off valvesĀ and regulatory valves. Within each category, there areĀ manyĀ types of valves, each with their own handle and use. The types of valvesĀ that we'll cover in this guide are:
Shut Off Valves

Shut-off valvesĀ that are used primarily to start or stop theĀ flowĀ of fluidĀ in the pipe. A shut-off valveĀ can beĀ operatedĀ manually, or automatically using external controlĀ such as an actuator. An electric motor is a type of actuatorĀ that can be used to rotateĀ the handle of a valve. This way the shut-off valveĀ can be operatedĀ automatically.
There are many types of shut off valve:
Ball valve
Gate valve
Globe valve
Butterfly valve
BallĀ Valves

Ball valvesĀ are 2-way, 2-position valvesĀ used for shut-off or isolation of a system. 2-way valvesĀ mean there are two ports (in and out of pipe) and 2-position valvesĀ refer to open or closed.
Ball valvesĀ can also be 3-way or 4-way. Such multi-port valvesĀ are used in pipingĀ that require more than one source ofĀ flow. For example, if your home is equipped with two sinks. To stop the water supply from one of the sinks, you may use a 3 way shut-offĀ valves.
A ball valve controlsĀ a liquidĀ or gas flowĀ using a rotary ball with a hole in the middle. When we rotateĀ the ball valve, the ball aligns with the valveĀ cylinder. This allows liquidĀ or gas to flowĀ through.Ā A slot is machined on the top of the ball. The stemĀ fits into this slot and is bolted to the handle on the other end. As you turn the handle, it turns the ball to open or closeĀ the valve.
Ball valvesĀ have a fast shut-off with only a quarter-turn or 90Ā° turn to closeĀ the valve. This makes them easier to use for applications where frequent opening and closingĀ is required.
GateĀ Valves

Gate valvesĀ work by inserting a rectangular gate or wedge into the path of a flowingĀ fluid. Similar to a ball valve, the stemĀ is connected to the handle of the gate valve. The other end of the stemĀ is connected to a rectangular wedge.
When the hand-wheel is turned, it rotatesĀ the stem. This makes the threads on the stemĀ unscrew.Ā Due to movement of the threaded rod, the rectangular wedge attached at the other end of the stemĀ also moves up. This opens the valveĀ and fluidĀ flowsĀ through the pipe.
Gate valvesĀ are similar to old water taps. They are considered multi-turn valves, as it takes more than one 360Ā° turn to fully open or closeĀ the valve. Due to this reason, they are used in applications that does not require frequent opening and closing.Ā Gate valvesĀ are easier to clean and maintain though, making them suitable for applications that involveĀ slurries.Ā
Globe Valves
A globe valveĀ is used to stop, start and regulateĀ flow. Unlike a gate valve, a globe valveĀ can controlĀ the flowĀ of fluid. A 2-way globe valvesĀ are used for single inlet flowĀ and outlet flow. When more than one inlet and single outlet, a 3 way or 4 way globe valvesĀ is used.
InĀ globe valves, a disc is used to block theĀ flowĀ through the pipe. The other parts used such as stem, bonnetĀ are similar to gate valves.Ā The disc within the globe valveĀ is designed to move up and down from the seat. These vertical movements allow the space between the disc and the seat to change slowly, giving the valveĀ good controlĀ over flowĀ of fluidĀ through the pipeline.Ā The further apart the disc and seat, the more liquidĀ that will flowĀ through the valve. This controlĀ of fluidĀ flowĀ is not possible in a gate valve.

The workings of a globe valveĀ is similar to tap used in wash basin and kitchen; as youĀ rotateĀ the tap handle, fluidĀ flowĀ starts gradually and will reach maximum when fully opened.Ā In a globe valve, when the disc is fully lowered, the fluidĀ flowĀ is shut off.Ā When the disc is fully raised, the fluidĀ flowsĀ at its maximum rate.Ā
Globe valvesĀ are used for regulatingĀ and shut off applications in swimming pool drains and lubrication systems.Ā All these systems require starting, stopping and regulatingĀ flowĀ for its application.
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Butterfly Valves

Butterfly valvesĀ are shut-offĀ valvesĀ that are used to start and stop liquidĀ flow. They are made to be specifically compact for tight spaces.
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In butterfly valves, a disc is used similarly to a globe valve. When the disc within a butterfly valveĀ is completely sideways, fluidĀ is permitted to flow; when the disc of a butterfly valveĀ is upright, the flowĀ of fluidĀ is blocked completely.Ā
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Butterfly valvesĀ are a quarter turn rotational motion valve, making them great for quick-acting situations. Similarly to ball valves, butterfly valvesĀ are easier to use for applications where frequent opening and closingĀ is required.
Regulating Valves
While shut-off valvesĀ are used toĀ start and stop the flowĀ inside the pipe, regulatingĀ valvesĀ are a type of valveĀ used toĀ controlĀ the flow. RegulatingĀ valvesĀ can be considered control valves. Control valvesĀ also controlĀ fluidĀ flow, hence their name.
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RegulatingĀ valvesĀ are operatedĀ and controlledĀ automatically usingĀ pressureĀ difference. An actuatorĀ is used to actuateĀ valvesĀ in order to turn them one way or another. There are many types of actuators, such as hydraulic actuators, pneumatic actuators, mechanical actuators, and more. ActuationĀ is the process of actuatingĀ a valve.
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There are many types of valvesĀ that are regulatingĀ valves:
Check valve
PressureĀ relief valve
PressureĀ regulatingĀ valve
Check Valve

A check valveĀ opens with forward flowĀ and closesĀ against reverse flowĀ to act as a safety device for fluidĀ to flowĀ in only one direction. Check valvesĀ are generally installed to prevent backflow. Backflow is when waterĀ flowsĀ backward in the supply line due to pressureĀ changes.Ā
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Check valvesĀ require a minimum pressureĀ difference between inlet and outlet to open the valveĀ and allow fluidĀ flowĀ through it. If there is minimum pressureĀ difference or inlet pressureĀ becomes equal to outlet pressure, then the check valveĀ opens. If the inletĀ pressureĀ starts to fall due to damage to parts, then the check valveĀ will closeĀ automatically. Depending on the check valveĀ design, the closingĀ mechanismĀ can change.
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PressureĀ Relief Valve

PressureĀ relief valvesĀ are spring-loaded safety valves. PressureĀ relief valvesĀ are normallyĀ closedĀ but are opened automatically when the safe pressureĀ limit is crossed. The safe pressureĀ limit is the pressureĀ at which the valveĀ should be operated.
We release the pressureĀ to protect the system from high pressureĀ damage. That is why the outlet of the pressureĀ relief valveĀ is connected to the tank. This ensures pressureĀ does not build up in the system.
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Similar to the spring in a pressureĀ cooker whistle, there is a spring inside the pressureĀ relief valve. This spring is present in the middle of the valve, also called the bonnet. The spring helps to actuateĀ the valveĀ depending upon the pressure.
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The safe pressureĀ limit of the pressureĀ relief valveĀ can beĀ changed by adjusting spring tension. An adjustment screw is used to set the pressureĀ of the relief valve. As you loosen or tighten the screw, the tension in the spring is adjusted. This will increase or decrease the set pressure.
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In pipes, if the fluidĀ reaches pressureĀ higher than set limit, then the fluidĀ pushes the disc upwards. This pushes the spring attached to the disc. The spring gets compressed and disc is moved upwards to open the valve.
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If the fluidĀ pressureĀ from inlet is reduced below set limit, the spring tries to come to its original position. This is because spring force becomes greater than fluidĀ pressure. This causes the disc to come down and closeĀ the valve.
Pressure Regulating Valve

PressureĀ regulatingĀ valvesĀ are also known asĀ pressureĀ reducing valve. It is normally an open typeĀ valveĀ thatĀ maintains a constant pressureĀ in the pipeline even when there are fluctuations in the inlet and outlet pressure.
PressureĀ regulatingĀ valvesĀ consist of the following elements:
PoppetĀ valve
Spring
Sensing element such as a diaphragm or a piston
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As the outletĀ pressureĀ increases, approaching the set pressureĀ of poppet valve, the fluidĀ is diverted over the diaphragm. The fluidĀ pressureĀ under the diaphragm begins to overcome spring pressure. This forces the poppet valveĀ upward and closesĀ the valve.
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When the outlet pressureĀ drops below the set point of the valve, the spring pressureĀ overcomes the outlet pressure. This forces the valveĀ downward, opening the valve.
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AsĀ pressureĀ in the inlet side becomes more than setĀ pressure, the fluidĀ enters on the top of the poppet and closesĀ the valve. The valveĀ remains closedĀ until inlet pressureĀ becomes equal to outlet pressure.
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FAQs
What is a valve?
A valveĀ is a device used to controlĀ the flowĀ of a fluidĀ in a pipeline. It can either stop, regulate, or start the flowĀ of liquidĀ or gas, depending on the type and application. ValvesĀ can be operatedĀ manually or automatically using actuators.
What is the function of a shut-off valve?
Shut-off valvesĀ start or stop the flowĀ of fluidĀ in a pipe. These valvesĀ can be operatedĀ manually or automatically through an actuator. Common shut-off valvesĀ include the ball valve, gate valve, globe valve, and butterfly valve.
What is a gate valveĀ used for?
A gate valveĀ insert a rectangular wedge into the path of a flowingĀ fluid. It is a multi-turn valve, meaning it requires several turns to open or closeĀ fully. These valvesĀ are used where frequent opening and closingĀ are not required.
What is the difference between a globe valveĀ and a gate valve?
A globe valveĀ can regulateĀ the flowĀ of fluid, unlike a gate valveĀ that is only used stop or start the flow. The globe valveĀ uses a disc that moves vertically to controlĀ the space between the disc and seat, allowing gradual controlĀ of the fluidĀ flow.
How does a butterfly valveĀ function?
A butterfly valveĀ is a quarter-turn valveĀ used to shut off or start fluidĀ flow. It uses a disc that rotatesĀ 90Ā° to block or allowĀ fluidĀ flowĀ through the pipes. Butterfly valvesĀ are ideal for quick-acting applications due to their simple design.
What is a check valve?
A check valveĀ allows fluidĀ to flowĀ in one direction and prevents backflow. It opens when theĀ fluidĀ flowsĀ in the correct direction and automatically closesĀ if the flowĀ reverses, acting as a safety feature in pipelines.
What is a control valve?
A control valveĀ is a type of valveĀ used to regulateĀ the flowĀ of fluidĀ (liquid, gas, or slurry) in a system. Control valvesĀ automatically adjusts the flow rate, pressure, or temperature based on input signals from a controlĀ system, allowing for precise controlĀ over the process. Control valvesĀ are commonly used in industrialĀ applications, such as chemical plants, water treatment facilities, and HVAC systems, to ensure optimal performance and safety.
How does a control valveĀ work?
Control valvesĀ use a combination of a valve body, actuator, and sensor to regulateĀ fluidĀ flow. The actuatorĀ (which can be pneumatic, hydraulic, or electric) adjusts the position of the valve's internal componentsĀ (such as a disc, ball, or plug) based on signals from a controlĀ system. These signals, often from a pressureĀ or temperature sensor, tell the actuatorĀ to open or closeĀ the valveĀ to maintain the desired flow rate, pressure, or temperature.
What is a plug valve?
A plug valveĀ is a type of valveĀ that controlsĀ the flowĀ of fluidĀ by using a cylindrical or tapered plug that can be rotatedĀ to open or closeĀ the flowĀ path. The plug has one or more holes (ports) that align with the pipe's flowĀ path when the valveĀ is open. Plug valvesĀ are typically used for on/off or diversion applications and can handle both liquidsĀ and gases.
How does a plug valveĀ work?
A plug valveĀ operatesĀ by rotatingĀ a cylindrical or tapered plug inside the valve body. The plug has one or more ports that line up with the inlet and outlet ports of the valveĀ when it is turned to the open position, allowing fluidĀ to pass through. When the valveĀ is closed, the ports are rotatedĀ away from the flowĀ path, stopping the fluidĀ from passing through. The operation is typically manual, but can also be automated with an actuator.
What is the purpose of a pressureĀ relief valve?
A pressureĀ relief valveĀ is used to prevent excessive pressureĀ buildup in a system. It opens automatically when the pressureĀ exceeds a safe limit, allowing the fluidĀ to escape and protecting the system from damage.
How does a pressureĀ regulatingĀ valveĀ work?
A pressureĀ regulatingĀ valveĀ maintains a constant pressureĀ in the pipeline, regardless of pressureĀ fluctuations at the inlet or outlet. It automatically adjusts to maintain the set pressureĀ by controllingĀ the flowĀ of fluid.
What is an actuatorĀ in a valve?
An actuatorĀ is a device that automatically operatesĀ a valve. It uses an external controlĀ like pressureĀ difference, electric motors, or hydraulic systems to open or closeĀ the valveĀ without manual intervention. Common types of actuatorsĀ include pneumatic actuatorsĀ and hydraulic actuators.
Why would I need to use a ball valveĀ over a globe valve?
A ball valveĀ is ideal for applications where quick shutoff is needed, with only a 90Ā° turn required to close. On the other hand, a globe valveĀ is better suited for regulatingĀ flow, as it provides finer controlĀ over the flow rate.
Can a valveĀ be operatedĀ automatically?
Yes, many valves, especially shut-off valves, can be operatedĀ automatically using actuators. These actuatorsĀ use a pressureĀ difference or other controlĀ systems to open or closeĀ the valveĀ without human intervention.
What is aĀ flangedĀ valve?
A flangedĀ valveĀ is a type of valveĀ that has flanges on either side, which are used to connect the valveĀ to a pipeline. The flanges are typically bolted together, ensuring a tight sealĀ and preventing leaks. These valvesĀ are often used in systems that handle high-pressureĀ or high-temperature fluids.
Quiz
Question #1: What is the primary function of aĀ valve?
To increase the flowĀ of fluid
To decrease or stop the flowĀ of fluid
To monitor the pressureĀ of fluid
To regulateĀ the temperature of fluid
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Question #2: WhichĀ valve typeĀ is commonly used for quick on/off flow controlĀ and can operateĀ with a 90Ā° turn?
Gate valve
Plug valve
Ball valve
Globe valve
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Question #3: Which valve typeĀ uses a tapered or cylindrical plug to controlĀ the flowĀ of fluid?
Gate valve
Plug valve
Ball valve
Butterfly valve
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Question #4: Which of the followingĀ valvesĀ is specifically used for regulatingĀ flowĀ and pressureĀ in a pipeline?
Check valve
Gate valve
PressureĀ relief valve
Butterfly valve
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Question #5: WhichĀ type of valveĀ is designed to prevent backflow in a system?
PressureĀ relief valve
Check valve
Globe valve
Ball valve
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