Plumbing Valves | 9 Types Of Valves In Plumbing

What Is a Plumbing Valve?

Plumbing Valves are a device that controls, control, or directs the flow of fluid by opening, closing, or by a partial obstruction.

A valve is a mechanical device that controls the flow and pressure of a fluid in a system or process. So basically, it controls the flow and pressure.

What Is Plumbing?

Plumbing can be defined as practice, materials, and fixtures, installing, erecting piping, fixtures, appliances, and appeals in relation to sanitary or storm drainage facilities, a venting system, and public or private water supply systems Used in placing and replacing.

Types of Valves In Plumbing

The following types of valves in plumbing are used in piping depending on the requirements. The cost of plumbing valves in a piping system ranges from 20 to 30% of the total piping cost. And the value of a given type and size of the plumbing valves can vary by 100%.

That means if you choose a ball valve over a butterfly valve for the same function. It may cost you more. Therefore, the economics of the process plant, as well as the selection of plumbing valves for operation are essential.

The following are types of water valves used in the plumbing system,

Gate Valve
Globe Valve
Check Valve
Plug valve
Ball Valve
Butterfly Valve
Needle Valve
Pinch Valve
Pressure Relief Valve

Types of Valves

The following are the most used plumbing valves types,

1. Gate Valve

It is a linear motion valve used to start or stop the flow of fluid. In service, these valves are in either fully open or fully closed positions. The Gate Valve is the most commonly used valve in any process plant.

When the gate valve is fully open, the disc valve of the gate valve is completely removed from the flow. So virtually no resistance to flow.

This is due to the very low pressure when the flow passes through the gate valve. To achieve proper sealing, when the valve is completely closed, it is necessary to make a 360 ° surface contact between the disc and the seats.

Gate valves should not be used for flow regulation or throttling as accurate control is not possible. The high velocity of flow in partially open plumbing valves can cause erosion of disc and seat surfaces and also create vibration and noise.

Types of Gate Valves

There are three ways to classify the gate valve.

Types of Disk
Solid taper wedge
Flexible wedge
Split wedge or Parallel disks Valve
Types of Body Bonnet Joint
Screwed Bonnet
Bolted-Bonnet
Welded-Bonnet
Pressure-Seal Bonnet
Types of Stem movement
Rising Stem or OS & Y Type (Outside Stem and Screw Type)
Non-rising Stem type

Types of Gate Valve Based On Disk

1. Solid Wedge Gate Valve

Solid wedge is the most common and widely used disk type because of its simplicity and robustness. A valve with a solid wedge can be installed at any position and is suitable for almost all fluids. It can also be used in a turbulent flow.

However, it does not compensate for changes in seat alignment due to pipe load or thermal expansion. So, this type of disk design is the most susceptible to leakage. If used in high-temperature service, the thermal wedge is subject to thermal locking.

Thermal locking is a phenomenon in which the wedge is trapped between the seat due to the expansion of the metal. Solid-wedge gate valves are commonly used in medium to low-pressure-temperature applications.

2. Flexible Wedge Gate Valve

The flexible nail is a one-piece solid disc with a cut around the circumference. These cuts vary in size, shape, and depth. Narrow cuts on a shallow, paved circumference give less flexibility but retain strength.

A cast-in recess or a deeper and wider cut on the wedge perimeter gives more flexibility but compromises strength. This design improves seat alignment and provides better leak tightness.

This improved performance in situations where thermal binding is possible. Flexible wedge gate valves are used in steam systems.

Thermal expansion of the steam line sometimes results in the deformation of the valve bodies which can lead to thermal blinds.

The flexible gate allows the gate to flex as the valve seat is compressed due to the thermal expansion of the steam pipeline and prevents thermal blinds.

The disadvantage of flexible gates is that the line fluid collects in the disk. These can result in corrosion and eventually weaken the disc.

3. Split Wedge or Parallel Disks Gate Valve

The split wedge disc consists of two solid pieces and is gripped with the help of a special mechanism. You can only see it in the images. In this case, half of the disc is out of alignment;

The disc is free to adjust itself to the seating surface. The partition disk can be in the shape of a wedge or a parallel disk type.

Parallel disks are spring-loaded, so they are always in contact with the seats and provide bi-directional sealing. The split wedge is suitable for handling non-conditioning gases and liquids at normal and high temperatures.

The freedom of movement of the disc prevents thermal bonding even if the plumbing valve is closed when a line is cold.

This means that when a line is heated by a fluid and it expands it does not form a thermal blind.

A. Types of Gate Valve Based on Body, Bonnet Connection

1st is a screwed bonnet: it is the simplest design available and is used for inexpensive valves.

2nd is bolted bonnet: it is the most popular design and is used in a large number of gate valves. This requires a gasket to seal the joint between the body and the bonnet.

3rd is Welded-Bonnet: this is a popular design, where decompression is not required. They are lighter in weight than their bolt-bonnet counterparts.

4th one is Pressure-Seal Bonnet: this type is used extensively for high-pressure high-temperature applications. The higher the pressure of the body cavity, the greater the force on the gasket in the pressure valve.

B. Types of Gate Valve Based on Stem Movement

1. OS & Y Gate Valve or Rising Stem (Outside Stem and Screw Type)

For a mounting stem valve, the stem will move up while opening the valve and move down when you close the valve.

You can see this in the image. In the inside screw design, the threaded portion of the stem is in contact with the flow medium, and when you open the valve, the handwheel arises along the stem.

Whereas in the case of the external screw design, the sole smooth part is in contact with the flow medium and the stem will rise above the handwheel. This valve is also known as OS & Y valve. OS&Y stands for Steam and Outside York.

2. Non-rising Stem Gate Valve or Insider Screw Valve

There is no upward movement of the stem in the type of stem that grows. The valve disc is threaded internally. In this type of plumbing valve, the stem thread is exposed to the flow medium.

Therefore, this design is used where space is limited to allow linear stem movement, and the flow medium does not cause erosion, erosion, or erosion or erosion for the stem material. This type of valve is also known as an insider screw valve.

Gate Valve Applications

Gate valves are used in almost all fluid services such as air, fuel gas, feedwater, steam, lubricating oil, hydrocarbons, and most all services.

Some special gate valves are also used in slurry and powder products such as knife gate valves.

Benefits of Gate Valve

The pressure drop during operation is very low.
Most gate valves can be used as bi-directional
They are suitable for high-pressure and temperature applications and require little maintenance

Disadvantages of Gate Valve

It cannot be used to control flow.
A gate valve is slow in operation. It takes time to open and close which is also good because it reduces the chances of hitting the hammer.
When partially open it produces vibration and noise.
Lapses and grinding of seats are more difficult to repair due to limited access.

2. Globe Valve

The globe valve is a linear motion plumbing valve used to stop, initiate, and control flow. The globe valve disc may be completely removed from the flow path, or it may close the flow path completely. During the opening and closing of the valve, the disc moves perpendicular to the seat.

The leakage from the globe valve seat is less than that of the gate valve, mainly due to the right-angled contact between the disc and the seat ring, which allows tight sealing between the seat discs.

Types of Globe Valve

Depending on the type of body there are three types of globe valves;

Z types
Y types
Angle Types

1. Z types of Globe Valve

The simplest design and most common type is a Z-body. Z-shaped partitions have seats inside the circular body.

The horizontal seating arrangement of the seat allows the stem and disc to travel perpendicular to the axis of the pipe resulting in too much pressure.

The valve seat is easily accessible through the bonnet which is attached to a large opening at the top of the valve body. The stem passes through the bonnet like a gate valve.

This design simplifies manufacturing, installation, and repair. This type of valve is used where pressure drop is not a concern and throttling is required.

2. Y types Globe Valve

The Y-type design is a solution to the high-pressure drop problem in Z-type valves. In this type, the seat and stem are angled at approximately 45 ° to the pipe axis.

This type of valve is used in high-pressure and other critical services where pressure drop is concerned.

3. Angle types Globe Valve

The angle globe valve changes the direction of flow by 90 degrees without using an elbow and an additional pipe weld.

Disc open against the flow. Globe valves can also be used in fluctuating conditions, as they are capable of handling the slugging effect.

Globe Valve Types based on Body Bonnet Connection

It is the simplest design available and is used for inexpensive valves.

Bolted-bonnet: It is the most popular design and a large number of globe valves are used. This requires a gasket to seal the joint between the body and the bonnet.

Welded-Bonnet: This is a popular design where disassembly in it is not required. They are lighter in weight than their bolt-bonnet counterparts.

Pressure-Seal Bonnet: This type is used extensively for high-pressure and high-temperature applications. The higher the pressure of the body cavity, the greater the force on the gasket in the pressure valve.

Application of Globe Valve

It is used in high-point vents and low-point drains when leakage tightness and safety are major concerns. Otherwise, you can use a gate valve to drain and vent.
It can be used in the feed water, chemical, air, lubricating oil, and almost all services where pressure drop is not a problem.
This valve is also used as an automatic control valve, but in that case, the stem of the valve has a smooth stem instead of being threaded and is opened and closed by lifting the action of the actuator assembly.

Advantages of Globe Valve

Closed better than the gate valve
Good for continuous operation as there is no fear of wearing a seat and disc
For easy repair, as the seat and disc can be accessed from the valve top
Faster operation than the gate valve due to shorter stroke length
Usually operated by an automatic actuator loss.

Disadvantages of Globe Valve

High head loss from two or more right angles to the fluid flowing within the valve body.
Obstructions and discontinuities in the flow path cause a high head loss.
In a large high-pressure line, pulsation and impact can damage internal trim parts.
A large valve requires considerable power to open and create noise during operation.
It is heavier than other valves of similar pressure rating.
Costlier than gate valves.

3. Check the Valve

The plumbing valves that are used to prevent backflow in a piping system is known as check valve. It is also known as a non-return valve or NRV.

The pressure of the fluid passing through a pipeline opens the valve, while any reversal of the flow will close the valve.

Types of Check Valves

Swing Type
Top Hinged
Tilting disk
Lift Type
Piston Type
Ball Type
Dual Plate Type
Stop Check Valve

1. Swing Check Valve

Discs in swing-type valves are interlocked as they open or close completely. This valve operates when there is a flow in the line and stops completely when there is no flow.

The turbulence and pressure drop in the valve is very low. Disc and seat designs can be metal-to-metal or metal-to-metal.

Typically, seat angles are in the range of 5 to 7 degrees. Larger seat angles reduce disc travel, resulting in quicker closing, and reducing the possibility of a water hammer. A vertical seat has a 0-degree angle.

The swing-type valve allows full, unobstructed flow and closes automatically as the pressure decreases. Usually installed in combination with gate valves as they provide relatively free flow combinations.

A basic swing-type valve consists of a valve body, a bonnet, and a disc that is attached to a hinge.

2. Tilting Disc Check Valve

Tilting disc-type valves are designed to overcome some weaknesses of traditional swing-type valves. The design of the tilting disc enables the valve to fully open and remain stable at low flow rates and close quickly when the forwarding flow is closed.

The dome-shaped discs float inflow and fluid flow both below and above the disk surfaces. Since the disc is spring-filled, when the forward flow pressure is reduced, the spring force helps the valve close rapidly.

The tilting disc type is available in valve wafer type and lag type design.

3. Ball Type and Plug Type Lift NRV

The seat design of a lift check valve is similar to that of a globe valve.

Lift check valves are particularly suitable for high-pressure service where the flow velocity is high. The disc is fully set on the seat with full contact.

When the flow enters the bottom of the seat, a disc is lifted from the seat by upward flow pressure. When the flow stopped or reversed, the backflow and gravity forced the disc downward to set the seat. Commonly used in piping systems that use globe valves as flow control valves.

Here you can see plug or piston-type and ball-type check valves. These valves provide better leak-tight characteristics to swing check valves.

Some designs in plug type use a spring to maintain the disk in a closed position. This will ensure that the valve allows fluid flow only when there is sufficient pressure in the flow direction.

A ball-type valve is very simple because it only works on the principle of gravity. When there is sufficient pressure in the flow, it lifts the ball upwards, but when the pressure decreases the ball is bent downwards and the opening is closed.

4. Dual Plate / Dual Disc Check Valve

The seat design of a lift check valve is similar to that of a globe valve.

Lift check valves are particularly suitable for high-pressure service where the flow velocity is high. The disc is fully set on the seat with full contact. When the flow enters the bottom of the seat, a disc is lifted from the seat by upward flow pressure. Commonly used in piping systems that use globe valves as flow control valves.

Here you can see plug or piston-type and ball-type check valves. These valves provide better leak-tight characteristics to swing check valves.

Some designs in plug type use a spring to maintain the disk in a closed position. This will ensure that the valve allows fluid flow only when there is sufficient pressure in the flow direction.

5. Dual Plate / Dual Disc Check Valve

A dual plate check valve is known as a butterfly check valve, folding disc check valve, double-disc, or split disc check valve.

As the name suggests, the two halves of the disc move along the forward flow towards the centreline, and the two halves with the reverse flow open and rest on the seat to close the flow (flopping action).

The use of dual plate check valves is popular in low-pressure liquid and gaseous services. Its lightweight and compact construction makes it a better choice when space and convenience are important.

It is 80 to 90% lighter than traditional full-body check valves. Often used in systems that used butterfly valves. The cost of installation and maintenance is very low compared to other types.

6. Stop Check Valve

The stop check valve is a combination of a lift check valve and a globe valve. It can be used either as a check valve or as a stop valve like a globe valve.

These valves can be closed with the help of a stem that is not connected to the valve disc during normal operation and making it possible to use these valves as regular NRVs.

These valves are available in T, Y, and angle patterns. Swing check and piston lift type valves are commonly used as stop check valves.

4. Plug Valve

This type of valve is a quarter-turn rotary motion that uses a tapered or cylindrical plug to stop or start the flow. The disk plug is shaped, with a passage to pass the flow.

The plug valve is used as an on-off stop valve and is capable of providing bubble-tight shutoff. Plug valves can be used in a vacuum for high-pressure and temperature applications.

Types of Plug Valves

These valves are available in either a lubricating or non-lubricating design and with different styles of the port opening through plugs.

1. Lubricated Plug Valve

A lubricated plug valve has a cavity in the middle along the plug’s axis. The small check valve under the injection fitting prevents the sealant from flowing in the reverse direction after being injected into the cavity.

The plug surface is continuously lubricated by a sealant that runs from the center cavity through the radial hole in the lubricant groove on the plug surface. Why do we need all this now? Many plug valves are of all metal construction.

The narrow gap around the plug may allow leakage, and if you further reduce the gap, this will increase friction and may get trapped inside the valve body.

The lubricant reduces the force required to open or close the valve and allows smooth movement of the plug. It also prevents plug corrosion.

The lubricating material must be compatible with the pipeline fluid.

Smooth plug valves are available in a larger size range, and they are fitted to work in high-pressure temperature services.

These valves are subject to reduced wear and provide better corrosion resistance in some service environments.

2. Non-lubricated Plug Valves

A non-metallic elastomeric sleeve is used in this type of valve. This type of sleeve is installed in the body cavity of the valve. The polished tape plugs act as a wedge and press the sleeve against the body.

This reduces the friction between the nonmetal sleeve plug and the valve body. Non-lubricating plug valves require minimal maintenance. Due to the non-metal seat, these valves are not used in high-temperature services.

5. Ball Valve

A ball valve is a quarter-turn rotary motion valve that uses a ball-shaped disc to stop the flow. It resembles a plug valve in many ways.

When the ball is in a port line, it allows flow. When you rotate the valve 90 degrees, the solid part of the ball stops the flow.

Most ball valves are of the quick-acting type, requiring a 90 ° turn of the valve handle to operate the valve.

But for larger-sized valves that require considerable force to open or close the valve, gear-driven actuators are used. With this arrangement, a small handwell is sufficient to operate a fairly large valve.

The following types of ball valves are used in piping

Floating
Trunnion Mounted
3 Way
Top entry
Side entry or split body
Three-piece body

1. Floating Ball Valve

The floating ball valve holds the ball in position by compression of two elastomeric seats against the ball.

Look at the highlighted part in the image and remember because when you explain to me about the trunnion-mounted valve you will see the difference.

The stem is attached to a slot at the top of the ball that allows the ball to rotate a quarter of a turn. The shaft allows for a certain amount of lateral movement of the ball that arises from the pressure acting upward on the ball.

This small lateral movement produces a load on the ball that presses it against the downstream seat which improves the tightness of the valve leakage. The floating valve is very difficult to operate when the upward pressure is high.

2. Trunnion Mounted Ball Valve

The solution to the problem of excessive torque required by floating type valves in high-pressure service. A small shaft extension known as a trunnion is set in the body. You can see it in the image.

In this design steam and ball act as a single unit. The ball is supported by two floating or spring-loaded seats that are in constant contact with the ball.

Trunnion ball design requires low operating torque. Therefore, reduces the size of the actuator and the total cost of the valve. This cost difference becomes an important factor as pressure class and valve size increase.

3. 3-Way Ball Valve

Depending on your requirements, you can arrange a three-way valve port.

One inlet and two delivered
With an inlet and an outlet changing a flow
Straight pass fluid without inlet

Three patterns are available. Venturi port type, full port type, and low port type. Full-port ball valves have an inside diameter equal to the inside diameter of the pipe.

This design allows pigging. In venturi and low-port types, the port is typically a pipe size smaller than the line size.

Ball-type discs can be fixed in an independent float or valve body.

6. Butterfly Valve

The butterfly valve is a quarter-turn rotary motion valve, used to stop, regulate and initiate flow. The butterfly valve has a small circular body.

Butterfly valves are suitable for large valve applications due to the compact, lightweight design that requires significantly less space than other valves.

Types of Butterfly Valves

Following are the types of butterfly valves,

Flanged ends
Wafer Type Ends
Luge type ends
Butt Welded Type Ends
Zero Offset Butterfly Valve
Double Offset Butterfly Valve
Triple Offset Butterfly Valve

The butterfly valve is a quarter-turn rotary motion valve, used to stop, regulate and initiate flow. The butterfly valve is a quick-open type. The 90 ° rotation of the handle can close or open the valve completely.

Generally, they are used in systems where a positive shut-off is not required. In this article, you will learn about the following types of valves.

Wafer type
Luge style type
Flanged Type
Butt
Welded Ends Type
Zero offset
Double offset
Triple offset

Larger butterfly valves are usually equipped with gearbox-type actuators, where the handwheel is attached to the stem through the gearbox. This will reduce the force but at the same time reduce the speed of operation.

This type of valve must be installed in the open position. If the valve closes during installation, the rubber seat valve will warp against the disc and it will be difficult to open.

1. Wafer Types

The wafer body is placed between pipe flanges, and the flange surrounds the valve body. A wafer-type butterfly valve is easy to install, but cannot be used as an isolation valve.

2. Lug Style

The retracted body consists of a spread of lugs at the periphery of a body that gives way to bolt holes that coincide with those in flanges.

3. Flanged Type

In this type, the body coincides with the flange dimension of the pipe.

4. Butt Welded Ends Types

This type of end is used in high-pressure services and is welded directly into the pipe.

5. Zero Offset Butterfly Valve

A zero offset design is used for plumbing valves used in low-pressure and temperature services. In this design, the disc and shaft axis is concentric with the valve body.

In the open position, the disk divides the flow into two equal parts, with the disk in the middle and parallel to the flow. This type of valve has a flexible seat.

There is friction between the disc and the seat during the full operation cycle which is a loss of the zero offset valve.

6. Double Offset Butterfly Valve:

In double offset, the disc is offset from the valve center line and also from the valve body center line. You can see it in the image where one and two are written.

The double offset smooths the opening and closing because friction is applied only during the first few degrees of opening, and the final few degrees of closing are about 10 degrees after opening and closing.

7. Triple Offset Butterfly Valve

In the triple offset design, the seating surface is the third offset created by the geometry design. The seat is mechanized in an offset conical profile resulting in a right-angled cone.

You can see this in the third image with a small increase in the seating angle. This ensures a frictionless stroke throughout its operating cycle.

The contact is made only at the endpoint of closure with a 90 ° angle as a mechanical stop; the Metal seated valve uses a triple offset design.

7. Needle Valve

Needle valves are similar in design to globe valves with the biggest difference being sharp needle-like discs. Needle valves are designed to give very precise control of flow in small-diameter piping systems.

They derive their name from their sharp-pointed conical discs and matching seats. A needle valve is a manual valve that is used for constant throttling of flow for regulation.

Needle valves are similar in design to globe valves with the biggest difference being a sharp needle-like disc.

Needle valves are designed to give very precise control of flow in small-diameter piping systems. They derive their name from their sharp-pointed conical discs and matching seats. The fluid flowing through the valve turns 90 degrees and passes through the orifice.

Due to the needle-shaped disc, a certain portion of the disc will pass before opening the seat, when the disc comes into contact with the seat, matching the taped design as a disc. This arrangement allows for a very gradual increase or decrease in the size of the opening.

The needle valve has a mesh and machined body. This body can be forged carbon steel or stainless steel depending on the requirements of the services. A seat can be soft, metal, or composite, similar to a globe valve.

Needle valves are typically used in smaller sizes and are provided with screwed or socket weld endings.

8. Pinch Valve

Pinch valves are also known as clamp valves. It is a linear speed valve. Used to start, regulate and stop fluid flow. It uses a rubber tube, also known as a pinch tube, and a pinch mechanism to control fluid.

The pinch valve is ideally suited for the handling of slurries, liquids with large amounts of suspended solids, and systems that efficiently deliver solid materials.

Pinch valves are also known as clamp valves. It is a linear speed valve. Used to start, regulate and stop fluid flow.

It uses a rubber tube, also known as a pinch tube and pinch mechanism, to control fluid. This valve is the simplest of any plumbing valve design.

Most pinch valves are open-style with the pinch tube exposed. However, another style completely encloses the pinch tube within a metal body.

9. Pressure Relief Valve

A pressure relief valve or pressure protection valve is used to protect the equipment or piping system in the event of an overgrowth event or vacuum. This valve releases the pressure or vacuum at a pre-determined set pressure.

The following are the types of pressure relief valves.

Recalling-type pressure relief device
Non-recycle type pressure relief device
Safety relief valve
Pressure relief valve
Vacuum relief valve
Pressure vacuum relief valve

Conclusion:

In Conclusion, plumbing valves play a crucial role in regulating the flow of water and ensuring the efficient functioning of plumbing system, in this article discussed various types of valves commonly used in plumbing.

Gate valves provide full flow control and are ideal for on/off applications, globe valves are suitable for controlling the flow rate and have a more precise control mechanism, check valves prevent backflow, ensuring a one-way flow of water, Plug valves can be used in a vacuum for high-pressure and temperature applications, ball valves offer quick and reliable shut-off capabilities, butterfly valves are versatile and widely used for larger pipes, Pressure relief valves safeguard against excessive pressure, preventing damage to the plumbing system, and pressure reducing valves regulate and maintain a consistent water pressure, thermostatic mixing valves control the temperature of water, promoting comfort and safety.

Understanding these various types of valves helps in selecting the appropriate for specific plumbing applications, ensuring efficient water flow control and system performance.

FAQs:

What are plumbing valves?

Plumbing valves are devices used to control the flow of water or other fluids in a plumbing system. They are essential for regulating water supply, shutting off water flow, and preventing leaks.

What is a ball valve?

A ball valve is a type of valve that uses a spherical disc (the ball) to control the flow of water. When the handle is turned, the ball rotates, allowing or blocking the flow of water.

What is a globe valve?

Globe valves are valves with a globe-shaped body and a movable disc that controls the flow of water. They offer precise control over the flow rate and are commonly used in applications that require throttling.

What is a solenoid valve?

A solenoid valve is an electronically controlled valve that uses an electromagnetic coil to open or close the flow of water. It is often used in automated plumbing systems or appliances.

What is a pressure relief valve?

A pressure relief valve is designed to automatically open and release excess pressure from a plumbing system. It helps protect the system from damage due to overpressure.

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