10 Common Types of Valves - Lorric

Contents

• 1. What is a Valve?
• 2. Valve and Plump
• 3. Types of Valves
  • 1 ) Linear Motion Valves
    • a. Check Valve
    • b. Diaphragm Valve
    • c. Globe Valve
    • d. Needle Valve
  • 2 ) Rotary Motion Valve
    • a. Ball Valve
    • b. Butterfly Valve
    • c. Pressure Reducing Valve
    • d. Gate Valve
  • 3 ) Quarter-turn Valve
    • a. Solenoid Valve
    • b. Pneumatic Valve
• 4. Valve Recommendation - KOSCN the Fluid Control Valve Experts

1. What is a Valve?

Valves are devices used in fluid and gas pipeline systems to control and adjust the flow of the medium by opening or closing. Valves can stop or allow the flow of gases and fluids, change the flow rate, control the flow direction, regulate downstream pressure, and release pressure when system pressure exceeds or falls below a preset range.

2. Valve and Plump

In industrial systems, valves control fluid flow, while pumps move liquids via pressure differences. Valves can be manually operated with a handwheel or handle or adjusted using automatic control systems.

A faucet is a simple valve, while more complex valves provide precise control, crucial in processes like semiconductor etching where chemical composition must be tightly regulated. In such cases, chemical solenoid valves with electric actuators and automatic control systems ensure accurate flow control. [1][2]

3. Types of Valves

The market offers hundreds of valve types. However, they can be broadly categorized into three types based on their motion: linear motion valves, rotary motion valves, and quarter-turn valves. Here are 11 common valves categorized by their motion type:

1 ) Linear Motion Valves

The opening and closing motion of a linear motion valve follows a straight line. The valve stem moves up and down within the valve body to open or close the valve, allowing the valve disc to tightly contact the seat. This typically results in good sealing performance. Common linear motion valves include:

a. Check Valve

Check valves, also known as non-return valves, are primarily used to prevent fluid backflow. They come in various types and are widely used in hydraulic systems. Due to their compact size, simple structure, and low cost, they are commonly found in household applications. Advantages Disadvantages   1. Prevents fluid backflow.   1. May affect system pressure.   2. Simple structure and low cost.   2. Only suitable for unidirectional flow.   3. Wide range of applications.   4. Low maintenance requirements.   5. Operates automatically. [3] | Check Valve working principle As shown in the diagram, the check valve operates as follows: fluid pressure pushes the valve open, allowing fluid to pass through. If the fluid attempts to flow backward, the valve closes, and the greater the backflow pressure, the better the seal. Check valves typically use a spring or gravity to close and do not require manual operation.

b. Diaphragm Valve

Diaphragm valves control fluid flow by using a flexible diaphragm to seal off the flow path. These valves are ideal for applications requiring corrosion resistance, making them commonly used in the chemical industry to handle various chemicals, solvents, and corrosive media. 
Diaphragm valvesare also frequently utilized in the food and pharmaceutical industries, as they effectively prevent cross-contamination and ensure the hygiene and safety of the fluids. [4] Advantages Disadvantages   1. Excellent sealing capabilities.   1. Limited pressure tolerance.   2. High corrosion resistance, suitable for corrosive fluids.   2. Not suitable for high-temperature environments.   3. No dead space, minimizing residue buildup and meeting high hygiene standards.   3. Narrow range of flow regulation. [5] | Diaphragm Valve working principle As shown in the diagram, a diaphragm valve consists of an elastic diaphragm within the valve body and bonnet. When the valve stem lifts, the diaphragm is raised, allowing fluid to flow through. Lowering the stem causes the diaphragm to block the inlet, stopping the flow. The separation of the actuating mechanism from the fluid by the diaphragm ensures excellent sealing, making diaphragm valves ideal for corrosive fluids, fibrous slurries, radioactive fluids, or other applications requiring contamination-free operation.

c. Globe Valve

Globe valves, also known as stop valves, regulate flow and pressure and are versatile. Originally named for their spherical shape, they are now sometimes called stop valves to avoid confusion with ball valves. 
Globe valves commonly used in heat exchange systems, globe valves allow direct fluid flow, making them suitable for high-viscosity fluids. They are ideal for water treatment, chemical, petroleum, and steam systems, as they prevent fluid accumulation and solidification inside the valve. [6] Advantages Disadvantages   1. Low resistance due to straight flow path.   1. Operating temperature is limited by seat material.   2. Available in various sizes, offering wide application range.   2. Higher flow resistance compared to other valves.   3. Suitable for frequent operation.   3. Relatively heavy in weight.   4. Low friction loss, ensuring long service life. | Globe Valve working principle Operation is as follows: turning the handwheel raises the valve stem. When the ball valve opens, the core moves up, allowing fluid to pass. The fluid follows a mirrored Z-shaped path inside the valve, entering low and exiting high, which increases resistance and reduces pressure. To close the valve, the core descends to tightly contact the valve seat, forming a seal to stop fluid flow.

In operation, fluid flows directly from the inlet to the outlet. This linear flow path reduces vortices and stagnation within the valve, helping to prevent high-viscosity fluids from solidifying or accumulating. Ball valves are commonly used in water treatment systems, chemical and petroleum industries, and steam systems. [7][8]

d. Needle Valve

Needle valves feature a needle-shaped plunger that precisely fits into the valve seat, allowing for fine control of fluid flow at low pressures. Needle valves are ideal for applications requiring small or constant low flow rates, such as vacuum systems, filling gas tubes, gas lasers, and similar equipment, as well as controlling idle fuel flow in carburetors.

＊Vernier Effect in Needle Valves: Due to the conical shape of the needle valve core, as the control moves axially (i.e., the core moves in and out), a diameter difference is created between the needle valve and the seat. This vernier effect, with minimal radial change, is a key mechanism for the needle valve's precise flow control. Advantages Disadvantages   1. Precise control of small flow rates.   1. Not suitable for high flow rates.   2. Suitable for low-pressure operations.   2. Higher pressure loss.   3. Can be used in vacuum systems.   4. Compact structure with good sealing capabilities. [9][10] | Needle Valve working principle The needle valve structure is shown below. It has a relatively small orifice with a long conical seat that can be screwed in and out to change the orifice opening. The screw end has a needle-like plunger that fits completely with the seat when closed, allowing for the regulation of very fine flow rates. Due to the height limitation of the valve body, fluid pressure loss is significant, and the narrow piping increases the risk of damage from suspended solids.

2 ) Rotary Motion Valve

Rotary Motion Valve opens and closes by rotating around an axis. The valve core usually operates in a rotating manner to open or close the flow path

a. Ball Valve

Ball valves control fluid flow using a spherical ball with a hole through its center. They offer excellent sealing performance and require minimal maintenance. Their simple operation makes them ideal for applications requiring quick shut-off and reliable sealing. Ball valves are widely used in various settings, including industrial oil and gas pipelines, chemical processes, and residential water systems. [11] Advantages Disadvantages   1. Capable of handling high pressure and high flow rates.   1. Potential for sediment buildup between the ball and seat.   2. Excellent sealing performance.   2. Requires higher operating torque, possibly needing additional actuation mechanisms.   3. Low flow resistance and easy maintenance.   3. Generally larger and heavier in size.   4. Can be used for flow control and diversion. [12] | Ball Valve working principle A ball valve has a hollow, ball-shaped core with a bore the same diameter as the pipeline. The handle turns the valve stem to rotate the core. When the bore aligns with the flow path, fluid passes through. To close the channel, a 90-degree turn of the handle blocks the fluid flow. [13][14]

b. Butterfly Valve

Butterfly valves, or flap valves, have a simple design and operate quickly by rotating a disc to control flow. They are suitable for managing large volumes of liquids or gases at low pressures. These valves are versatile and can handle various media, including water, oil, steam, and corrosive fluids. Common applications include water treatment, chemical and petrochemical industries, HVAC systems, and agricultural irrigation.

There are several types of butterfly valves, each suited for different pressures and applications:
i. Concentric butterfly valve: This type has a flexible rubber seat with a metal disc, suitable for the lowest pressure ratings.
ii. Double-offset butterfly valve (high-performance or double-eccentric): The seat and disc use different materials, allowing operation across a wider range of temperatures and pressures.
iii. Triple-offset butterfly valve (triple-eccentric): Features a laminated or solid metal seat, ideal for high-pressure systems and harsh environments, commonly used in industrial and energy sectors. [15][16] Advantages Disadvantages   1. Quick operation, ideal for frequent use.   1. Non-linear flow, causing uneven pressure.   2. Compact, lightweight, and easy to operate.   2. Less effective sealing.   3. Good flow control.   3. Can vibrate or make noise at high speeds.   4. Low pressure drop when fully open.   4. Not suitable for extreme temperatures or high-pressure conditions. | Butterfly Valve working principle As shown, a butterfly valve consists of a rotating disc typically located at the center of the valve body. During operation, the circular disc rotates around an axis with a maximum angle of 90 degrees, adjusting the medium flow by changing the angle. Since the disc is always present in the fluid, it increases flow resistance, causing local pressure loss.

c. Pressure Reducing Valve

A pressure relief valve is primarily a safety valve used to control or limit system pressure, preventing equipment failure, explosions, or fires due to excessive pressure. It operates through a spring or pressure adjustment device within the valve that controls opening and closing. This safety valve automatically opens at a set pressure value to release excess pressure. Pressure relief valves are crucial in various industrial applications, especially in high-pressure operations, ensuring industrial safety. A pressure relief valve is designed with a preset pressure at which it automatically opens when the system pressure reaches a certain level. This setting is typically operated by a valve spring or other mechanical elements such as weights or pilot valves.

The diagram shows a spring-operated pressure relief valve. When the system pressure exceeds the set threshold, the increased pressure pushes the valve core, compressing the spring and opening the valve. This releases the excess pressure or fluid, lowering the system pressure. Once the pressure returns to a safe range, the spring pushes the valve core back to its initial position, closing the valve. | Relief Valve working principle

d. Gate Valve

Gate valves use a movable gate to stop or allow flow, not to regulate it. They have low flow resistance when fully open and require minimal effort to operate. However, they need a longer time to open or close fully due to the gate's travel distance. [17] Advantages Disadvantages   1. Excellent fluid shut-off capability.   1. High-pressure differentials can cause water hammer.   2. Near-zero flow resistance when fully open.   2. Long operation time to open or close.   3. Suitable for various fluids, including liquids, gases, and steam.   3. Large size, requiring more space.   4. Can withstand high pressure and temperature. [18] Gate valves come in various types, typically featuring a simple structure without specific inlet or outlet installation requirements. As shown, they have a rising stem operated by a handwheel or motor, lifting the gate to open the flow path. 
Gate valves are suitable for larger pipe diameters. However, due to possible gaps or wear between the valve and the sealing surface, slight leakage may occur even when fully closed. Additional measures may be needed in applications requiring strict fluid sealing.

3 ) Quarter-turn Valve

Right-angle rotary valves operate with a 90-degree rotation, moving the valve core horizontally or vertically to open or close the flow path. These valves are ideal for applications requiring quick operation, often used in remote control and automation systems. Common right-angle rotary valves include solenoid valves and pneumatic valves.

a. Solenoid Valve

| Solenoid valve Solenoid valves use an electric current in a coil to create a magnetic field, controlling the valve's operation. They enable automated and remote control, making them ideal for applications like on-off control, test plant systems, and process control. Solenoid valves are also used in hydraulic jacks and truck hydraulic cylinders. [19][20] Advantages Disadvantages   1. Remote and quick control, ideal for automation.   1. Only for clean media, not for viscous or particulate fluids.   2. Compact, space-saving and easy to install.   2. Low pressure tolerance.   3. Low power consumption.   3. Needs stable power; won't work during outages.   4. Precise flow and direction control.   4. Requires regular maintenance for seals and coils. In a Normally Closed (NC) solenoid valve, the valve remains closed when the solenoid coil is not energized. Inside the NC solenoid valve, there is an armature surrounded by a solenoid. A spring connects the armature to a plunger. When not energized, the plunger blocks the passage. When current is applied, a magnetic field is generated inside the solenoid valve, pulling the plunger up and opening the passage, allowing fluid to flow through. Once the current is turned off, the plunger returns to its original position, blocking the fluid flow. [21]

b. Pneumatic Valve

Pneumatic valves, or air-operated valves, use air pressure to control fluid flow, suitable for high-pressure and high-temperature conditions. They are used in the energy sector for oil, gas, and water control, in the chemical industry for reactors and storage tanks, and in medical devices like ventilators and gas supply systems.
*The principle of a pneumatic valve is simple: it opens when there is no air and closes when there is air. [22] Advantages Disadvantages A pneumatic valve consists of two main parts: the bottom mechanical device and the top pneumatic device. Inside the mechanical device is the valve disc, which moves up and down to open or close the valve, similar to a stop valve (ball valve). The valve is covered by a bonnet, which can be opened for internal maintenance. The mechanical device is connected to the top device by a vertical spindle with a pointer that indicates whether the valve is open or closed. The top device contains a pneumatic actuator. When gas is injected through the port, the air pressure compresses the diaphragm and spring, pushing the valve core down to close the passage, preventing fluid flow. Conversely, when air is released, the spring expands, the valve core moves up, and the passage opens, allowing fluid to flow through. [23][24]

4. Valve Recommendation - KOSCN the Fluid Control Valve Experts

KOSCN is an international fluid control product manufacturing company. Since , it has achieved multiple patents for automatic control valve products through professional technology, from R&D to design. Its sales network extends from its headquarters in China to overseas distributors.

KOSCN Scientific MV304 Electric Diaphragm Valve

For more information, please visit YIYUAN.

KOSCN's Control Valves MV series diaphragm valves feature a fully plastic exterior design. The smooth flow path design enhances flow capacity beyond standard products. This series offers manual, pneumatic, and electric control options to meet diverse customer needs. Additionally, the product matches international installation dimensions and supports position feedback and proportional control modules. | KOSCN Scientific MV304 Electric Diaphragm Valve The MV304 electric diaphragm valve features easy installation and maintenance, as well as high safety. Its automation module uses a clamp-type connection, making assembly and disassembly very convenient. The LED interface allows for easy user settings and monitoring. Additionally, KOSCN's product torque is independently verified to ensure product longevity. Connection types include socket weld, butt weld, and various standard interfaces. It supports multiple signal ranges: 4-20mA, 0-20mA, 0-5V, 1-5V, 2-10V, making it an excellent automatic valve with superior regulation performance.

KOSCN BV202 Pneumatic Ball Valve

The KOSCN BV series plastic ball valve is a standard product featuring an internationally common structural design with high flow capacity and low torque. It supports modular expansion for electric and pneumatic control, enabling intelligent applications. Additionally, it offers various functions including on/off control, regulation, signal feedback, automatic reset, and fault alarm. | KOSCN BV202 Pneumatic Ball Valve The KOSCN BV202-PRO pneumatic ball valve is a chemical type product with a full plastic casing. It is lightweight, corrosion-resistant, and offers functions such as on/off, regulation, signal feedback, automatic reset, and fault alarm. The BV series comes with a position feedback switch and a positioner expansion module interface, making installation and operation easy. For safety, it features an overpressure margin design and a trapezoidal thread design for the union nuts to prevent disengagement, making it a safe and easy-to-operate ball valve.
⮕ KOSCN offers a variety of valves: KOSCN Valves

References

1. ^ valve - wikipedia
2. ^ List of Valves - adamantvalves
3. ^ 止回閥的作用及工作原理 - 多儀
4. ^ Diaphragm valve - wikipedia
5. ^ 隔膜阀工作原理 - 上海凯利科阀门有限公司
6. ^ globe valve - wikipedia
7. ^ 球型閥，停止閥，截止閥和閘閥別弄混了！區別大了！ - 証瓏
8. ^ Choosing the Right Valve for Optimal Performance - stromquist
9. ^ Needle valve - wikipedia
10. ^ 針閥 - 中郡
11. ^ HOW BALL VALVES WORK - convalve
12. ^ Ball valve - wikipedia
13. ^ Choosing the Right Valve for Optimal Performance - stromquist
14. ^ 閥門種類分不清楚嗎？三分鐘認識 - 寔黈
15. ^ 什麼是蝶閥？ - tourochina
16. ^ Butterfly valve - wikipedia
17. ^ Gate valve - wikipedia
18. ^ 球型閥，停止閥，截止閥和閘閥 - 証瓏
19. ^ Working Principles and Functions of Solenoid Valves in Industry - medium
20. ^ What Is A Solenoid Valve? - the engineering mindset
21. ^ 電磁閥 - wikipedia
22. ^ Air-operated valve - wikipedia
23. ^ How Pneumatic Valves Work - saVRee
24. ^ 气动阀门工作原理图 - 可拉伐

Valve material selection can be likened to fighting the mythical hydra. You focus on one head and think you have it beaten, and then suddenly, you are being attacked by two others. The problem is multifaceted because there are often several different physical and chemical processes at play. In addition, each valve component may have a different set of critical property requirements.

However, it is important to note that the mechanisms that cause valve components to degrade are complex and interconnected. While this discussion provides general guidance and strives to increase awareness of the various factors involved in material selection, each process and product needs to be thoroughly reviewed and understood to select the best material.

Understand the challenges

The first step in fighting a dragon is to identify which monster to face first, and this can be the most difficult part of the material selection process. There are many reasons for control valve component degradation, including erosion, adhesive wear, flashing, cavitation, corrosion, temperature extremes, and others. Several of these challenges often occur simultaneously, so it is important to identify and understand each problem.

Erosion (Figure 1) is the physical removal of material from a part due to particulate in the process fluid. This effect is common with slurries or liquids carrying abrasive particles, and it is usually countered by using hard materials or high strength coatings.

Despite the misleading name, adhesive wear is not related to aggressive glue, but results when metals rub against each other. This can be particularly troublesome for high cycle valves that must operate continuously for long periods of time. The key to addressing this problem is selecting the right combination of materials so they do not damage each other. Different materials have varying predispositions for galling — another name for adhesive wear — but there are some general guiding principles. Two soft materials in contact tend to gall, but a hard material paired with a relatively soft material will last much longer.

Flashing damage (Figure 2, left) occurs when a liquid passes through a valve and the downstream pressure is below the vapor pressure of the liquid. The liquid effectively boils as it moves through the throat of the valve, wearing metal in the process. Cavitation (Figure 2, right) is similar to flashing but is usually much more destructive. In this case, the liquid drops below the vapor pressure as it goes through the valve, but then the pressure rises, collapsing the bubbles. The resulting microjets and shock waves strike the valve walls, trim and downstream piping, inflicting damage.

Strength (or hardness) is a measure of how a material resists cutting, scratching or bending. Wear resistance indicates how well a material absorbs energy and avoids fracture or damage. Thermal expansion and corrosion resistance are self-explanatory, but the concept of “creep” is less common. Creep resistance is a solid material’s ability to avoid slowly deforming over long periods of stress while exposed to high temperatures. The best material for a particular application depends on how that component is being used in the valve, and this is why different valve components are often fabricated from varying materials.

For more information, please visit Other Valve Related Components.

Know your materials

Now that you have identified your adversary and know your goals, it is time to consider the array of arrows available in your quiver. The number of materials is expansive, and the breadth of proprietary and generic names often leads to confusion. For instance, “Hastelloy” is a common trade name, but there are over 20 versions of Hastelloy metals. There are at least six different alloys that are called Inconel. When referring to alloys, it is often best to use the generic names such as a UNS number or ASTM standard when possible to avoid confusion.

It is also important to understand how a particular metal protects against corrosion. Some materials employ passive corrosion resistance by forming a protective oxide layer which resists continued attack. Examples are stainless steel (SST), C-276 Hastelloy C and titanium. These materials tend to work well in oxidizing environments but work poorly in reducing environments, which attack the oxide layer. Other materials are more inert and do not readily react in many environments or do not rely as strongly on an oxide layer for protection. Examples of these materials include Monel, gold and Hastelloy B-3.

The Figure 5 table lists a variety of materials and their various strengths and weaknesses. It is important to note that this is an abbreviated list and only meant to illustrate the varying capabilities of the various material groups. This table should not be used as a guide for material selection.

Clearly, the number of options is huge, and the price differential from one alloy to another can be significant. When faced with a difficult material selection decision, it is advisable to discuss the options with your valve vendor. Often, several alloys may work, and the best choice for your particular application may be a combination of valve design and valve component material selection.

Conclusion

When faced with a difficult valve application, it is important to carefully and fully evaluate the situation to understand exactly what issues are at play. Often, there is a combination of physical processes (erosion, cavitation, etc.), as well as one or more corrosive processes, and it takes a complete understanding of the whole picture to fully address the problem. Once armed with that information, users can work with control valve vendors to select the best combination of valve design and component materials of construction to provide reliable, long-term service.

Fighting the hydra of material selection does not have to be a herculean effort when one is forearmed with process knowledge and has strong technical support in their corner. Using these skills, designers can solve vexing control valve headaches in their plant and become a process hero in no time.

Brett Hofman is an additive materials engineer for Emerson, researching how to realize the potential of additive manufacturing technologies in Emerson’s products. He previously held the role of materials engineer for Emerson’s flow control products, providing materials technical support on a global level to various departments across the company. He graduated from Iowa State University with Bachelor of Science in materials engineering in .

Emerson

www.emerson.com

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