Actuators for ball valves

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According to Wikipedia, valve actuator is a crucial component in an industrial environment. The actuator is responsible in opening and closing a valve which plays a key role in the industrial process.

hydraulic valve actuators

Source: Inst Tools

Hydraulic valve actuator utilize fluid in their mechanism. To elaborate, fluid plays a key component in the mechanical process of converting energy. This process enables a force that moves the piston which is responsible in opening and closing a valve.Pneumatic variant requires air pressure while hydraulic requires fluid.

However, the maintenance of the hydraulic supply system is pretty costly. Its quick operation may cause a faster soilage of the machine; thus, routinely check-ups should be done.

electric valve actuators

Source: Inst Tools

An electric valve actuator utilizes electricity in its mechanism. Unlike hydraulic and pneumatic actuators, it can operate without the presence of fluid and air pressure; making it perfect for environments with low temperatures where air and fluid may be rendered unusable.

Since it is powered by electricity, it can produce huge amounts of torque. With that, it comes with constant and configurable operating speeds.

A few cons to look out for are that it is a potential fire hazard due to the present variable, has slower operational speeds compared to other types, and tends to be costlier.

Manual valve actuators

Source: Direct Industry

Hand-operated levers or wheels engage a series of gears to open or close the valve in manual valve actuators. Manual valve actuators are limited to applications where automated or remote valve control is not required, despite their low cost and ease of use.

pneumatic actuators

Source: RS Components

Pneumatic valve actuators convert the energy in compressed air into mechanical motion, allowing for automatic or semi-automatic valve operation. They function by containing the air within a chamber and allowing it to expand, resulting in a pressure difference between the inside and outside of the chamber. The air is energized by the pressure differential. It can then be directed away from the chamber and toward the mechanical component that opens and closes the valve.

pneumatically actuated ball valves: types, symbols, and working principles

Pneumatic valve actuators are frequently found in oil refineries, chemical plants, power plants, water treatment, marine terminals and mining.

When compressed air is available in refineries, chemical plants, and pipeline compressor stations, the features and capabilities of on and off ball valve with pneumatic actuator are usually more advantageous. This is due to its working principle that match well where compressed air is frequent.

Rotary actuators

Source: Rotaru Cylinder

A mechanical device that converts electric, hydraulic, or pneumatic energy into rotary motion is known as a rotary valve actuator. This type of actuator is typically defined in degrees and revolves on a circular path. It can be set to finite or infinite, depending on the needs of the customer.

Double-acting valves

Source: Alibaba

Air is supplied to both sides of the piston in a double-acting actuator. Higher air pressure on either side causes the valve to open and close. A single-acting actuator, on the other hand, receives air on one side and uses one or more springs to return the piston to its original position.

Spring return valves

Source: Schlumberger

Spring-return actuators have only one side of the piston supplied with air or liquid, and the energy to move the mechanisms is provided by a spring on the opposite side. The valve is opened or closed using pneumatic or hydraulic pressure from the air or liquid, and the opposite motion is controlled by a spring.

Solenoid valves

Source: Tameson

The solenoid operates on the “electromagnetism” principle. When current flows inside a coil, a magnetic field can be generated in it; the concentration on the core of the flux of magnetic lines is the result when a metal core is situated in a coil, increasing the coil’s induction when compared to an air core.

Common on and off-ball valves with pneumatic actuator

One of the few misconceptions is that actuators and ball valves come in one. Ball valves pair with actuators, making them separate from one another. Actuators, like pneumatic, open and close ball valves. Furthermore, there are two types of pneumatic actuators and these are:

1. Scotch Yoke (dual)

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• Rack-n-Pinion (dual)

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They both perform the same rotational operation on quarter-turn ball valves, but they do so in a different mechanical manner. Both are available in spring return and double (direct) acting configurations. When power or supply air is lost, spring return pneumatic actuators will return to a “fail-safe position.” That position could be open or closed, depending on what is best for the system. When power or supply air is lost, double-acting pneumatic ball valves simply remain in their current position.

2-air actuated ball valve

Source: 91̽��

2-air actuated ball valve or double acting ball valve are your best option thanks to their affordability and durability. Because the absence of mechanical springs in most models eliminates the least durable component in the actuator, double-acting actuators are chosen for their lower cost and superior longevity. A high-quality double-acting actuator can often cycle millions of times before failing.

3-way pneumatic ball valve

Source: 91̽��

The 3-way ball valve is intended for use in a system with a constant flow of water. In systems where fluid mixing and diversion are required, the use of 2-way valves will necessitate the use of additional accessories.

Stainless steel pneumatic ball valve

Source: 91̽��

Stainless steel pneumatic ball valve endures longer. Because valves are designed to open and close, corrosion can be a major issue. When there is too much corrosion, a Ball Valve may break or become immobile. Stainless Steel Ball Valves will fare much better in harsher water conditions. This will result in a more durable valve.

pneumatic actuated ball valve manufacturers

Source: 91̽��

A valve manufacturer is considered a perfect option when there is quality control, well-suited after services such as maintenance, and their conformity to safety standards. 91̽�� valve manufacturer is business established for 31 years in China, the business center of industrialization.

Electrically actuated ball valve: symbol and working principle

The operating principle of the electric motor generates torque, which is transmitted to the valve stem via a shaft. This causes the ball valve to rotate. A gear system is connected to the electric motor shaft to achieve the required torque. The torque capacity is an important consideration when choosing an actuator. This option is well-suited in work environments where pneumatic and hydraulic are rendered unusable.

How do electrically actuated valve work?

A motor and gear train power electric actuators (also known as motorized or rotary ball valves). These are the most commonly used ball valve automation options. Electric actuators are used when there is no air supply to power pneumatic devices.

pneumatically actuated ball valves vs electrically: how to choose

• Power source

Power sources vary among pneumatic actuators and electric actuators. This is due to the presence of compressed air in the former, and the use of electricity in the latter.

• Speed

In terms of speed, pneumatic actuators tend to be quicker, however, this would mean shorter longevity as speed cause more cycle counts. On the other hand, electric actuators tend to be slower, but this is a benefit in their longevity as slower speeds require fewer cycle counts. Weighing these variables is a crucial component in choosing between the two.

• Duty cycle

As mentioned earlier, duty cycles between these two types vary in their speed. The speed directly affects the duty cycle counts of the actuator.

• Safety features/ standard

Normally, pneumatic actuators tend to be safer as there is no fire-hazard present in their mechanism. However, some situations call for the need for an electric actuator especially when there is a lack or no presence of compressed air at all. So, electric actuators tend to fall short of safety standards.

Other actuated valve types: hydraulic actuator valve

Source: Inst Tools

Fluid pressure is converted into motion by hydraulic actuators. They are used on linear or quarter-turn valves in the same way that pneumatic actuators are. Fluid pressure acting on a piston provides linear thrust for gate or globe valves. A quarter-turn actuator generates torque in order to provide rotary motion to a quarter-turn valve.

Control valve actuation

You may have noticed the focus of this article on how actuators perform with ball valves. To expand on the capabilities of actuators, other valves that pair well are globe valves, check valves, gate valves, and butterfly valves. These variants differ in how each stem is at work. For example, control valves are linear because its stem moves in an upward and downward motion. The globe valve is considered to be linear, as it is under the control valve.

As discussed earlier, the different types of actuators, mainly pneumatic, hydraulic, and electric utilize different variables such as air pressure, electricity, and fluids. All these types can cater to the different types of valves mentioned above.

The post Pneumatically actuated ball valves vs electrically�� actuated ball valves: which one to choose appeared first on 91̽��.

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A lot is to be known about the ball valve, from its different types, its vast uses and applications, and even the materials used to produce it. Another important thing to note about ball valves is the kind of port it has. Read on if you want to know more about ball valve ports.

Full port or full bore valves and standard port of standard bore valves are the two main ball valve port types. While the difference is not difficult to distinguish, its effect on the mechanism is apparent.

Port Design

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What are valve bore sizes?

The valve port may also refer to the valve bore or the hole in the ball valve where the medium passes through. The valve port types depend on the size of the bore in relation to the pipe that it serves as a valve. Full port valves have the same diameter hole as the pipe, while standard port valves are actually one pipe size smaller in diameter than the pipe it connects.

Full Port Valve

A Full port valve or full bore valve is a valve that has the same bore size as the flow path that it connects or serves as a valve to. This means that the flow pressure remains constant as it passes through the valve and no flow resistance is experienced. Apart from the full bore ball valve, other types like the full port gate valve, full port plug valve, and full port globe valve, are often full bore valves because of the nature of their structure.

Gate Valve

Image Source: Xhval

Plug Valve
Image Source: Xhval

Globe Valve
Image Source: Xhval

Reduced port valve

A reduced port valve, on the other hand, has a reduced-size port as its name suggests. The reduced bore ball valve dimensions are often smaller than 75% that of its original flow path.

Reduced Port Valve
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Standard port valve

Standard Port
Image Source: Xhval

A standard port valve or regular port valve is similar to a reduced port valve but is only reduced 75%-90% than the original size. Much like the reduced port valve, a standard port ball valve and a standard port gate valve is available but are not as common as full port valves. They are preferred only if applicable because it is less expensive compared to full port valves.

Full port ball valve vs standard port

How to tell the differences?

Ball valves can either be a full port ball valve or a standard port ball valve. Full port ball valves maintain the same size diameter, while standard port ball valves have a reduced diameter size compared to the pipeline it serves as a valve to.

Ball Valve Full Port

A full port ball valve may be expensive and may require more space compared to standard ball valves but its advantage lies in the consistent flow pressure. Full port valves are ideal for pipes carrying liquids and solids because of their unobstructed nature.

Ball Valve Standard Port

A standard port ball valve is preferred for gaseous media, especially since it costs less and takes up lesser space than a full port ball valve. Standard port valves are a cost-effective option if pressure flow is not an issue.

ball valves standard port or bore type benefits

Standard port or bore valves are preferred for applications wherein there are space limitations. These valves are more compact compared to their full bore cousins, making them also require less materials and are therefore more cost-effective to produce and purchase. If the reduction of flow pressure is not an issue for the pipeline application, then standard port or bore ball valves are the practical and more space-saving choice.

Full port or full bore ball valve

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Full port ball valves or full bore ball valves are basically ball valves that have a full bore or hole in the ball to allow for the passage of media through the valve to its connecting pipeline, such as 3 piece full port ball valve. These valves follow a straight path and an unrestricted flow. They have a larger body compared to a standard or a reduced port ball valve, as well as, a larger ball to accommodate a diameter that’s the same as the pipeline it connects. Little to no flow pressure loss is experienced when using a full bore or full port valve and no wear to the valve is added.

When to use full bore ball valve

full port ball valve for water heater

Full port ball valves are suited for applications like in a water heater since sediment or build-up can cause hot water to lose pressure. Build-ups and sediment are more common in standard port ball valves because of the reduction in diameter size and pressure loss when it passes through the valve.

full port brass ball valve

Image Source: Xhval

Full port brass ball valves are especially durable because of the material used to make it. Brass itself has high resistance to corrosion and the structure of a full port ball valve further adds to its durability since full port ball valves are less prone to wear because of the consistent flow pressure that it undergoes.

Stainless steel ball valve

Image Source: Xhval

A Stainless steel ball valve has additional properties that make it corrosion and abrasion-resistant. It performs well even under high pressure and temperature and requires less maintenance compared to other materials.

Standard port or standard bore ball valve

Image Source: Youtube

standard port valve

Standard port ball valves or standard bore ball valves are valves that have smaller diameter sizes compared to the pipeline that they connect or serve as a valve to. This makes them prone to the reduction of flow pressure and gives them a risk for cavitation.

When to use standard port or standard bore ball valve

Standard port or standard bore ball valves have the advantage of being cost-efficient and more adaptable to smaller spaces which is why they are a popular choice. They perform well in applications where pressure changes in the flow is no concern. If pressure flow is not an issue, a standard port or standard bore valve may prove advantageous because of its smaller size, lesser material, and reduced cost.

high flow ball valve

Image Source: Xhval

Full bore ball valves are considered to be high flow valves because of their ability to maintain flow rate and a consistent pressure.

Are There Other Valve Types Classified by Port Size?

While a gate valve and a globe valve typically do not have as extensive a classification as a ball valve, they do have different bore sizes depending on the application. Even though their bore sizes differ, gate valves and globe valves are essentially full bore or full port valves when they are fully open. Reduced bore designs are not usual but may be customized according to applications and to the standard.

full port vs standard port gate valve

Full port gate valve

Image Source: Xhval

Full port or bore gate valves have bore sizes that fit or conform to the size of the disc that is used to seal the valve. It is the usual design of gate valves and is more commonly produced and used.

Standard port gate valve

Image Source: Xhval

A standard port or bore gate valve or reduced port or bore gate valve is customized and must adhere to standards by the BSI and API. It is not as common as a full port or bore gate valve and not as widely produced, although manufacturers who customize valves may produce them according to the standards for the specific valve size.

Conclusion

Whether it is a full port valve, a reduced port valve, or a standard port valve that you are looking for, 91̽�� Valve Co., Ltd., is the top choice for all your valve needs. They have every port type and can customize the valve and the valve port according to your every requirement.

The post Full Port vs Standard Port Ball Valves: The Differences and Advantages appeared first on 91̽��.

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Let’s first consider the differences between valves and their applications in the excellent pump. A proper understanding of the primary uses of the check valve and foot valve will further answer the question of which valve option is better for the excellent pump. However, the foot valve is most applicable because it has an open end with a shield to trap debris.

Check valve

Image Source: xhval.com

Can I use a check valve instead of a foot valve for the well?

A check allows the flow of gas or fluid only in one direction. The valve’s external shells (bodies) are made of plastic or metal, and it operates automatically without any external control. They are small, simple, less expensive, and part of household items.

Check valves are mounted anywhere in the suitable pumps primarily to prevent the backflow of fluid, but a foot valve is placed at the bottom of the excellent pump. Furthermore, a check valve has two-port valves, but a foot valve has one opened end, and it’s ideal for use in suitable pumps because it keeps the pump primed and prevents water backflow.

Check Valve Uses

Let’s further consider the popular uses/application of a check valve;

To prevent damage to well pumps and other equipment such as centrifugal pumps caused by water backflow. Also, check valves help prevent mixing different media or contamination involving two reservoirs. For instance, in the case of water treatment plants, the check valve prevents the treated water from mixing with the contaminated one. They equally serve as vacuum breakers to allow air into the piping system to avoid interrupting the liquid flow.

Foot valve

Foot valve is which type of valve.

A foot valve is a non-return valve, a one-way valve, or a retention valve that permits fluid flow only in one direction. As the name implies, a ”foot valve,” it’s installed at the end of a pump or pipeline.

What is Foot Valve

A foot valve is a water pump valve having only one thread at the end of it. When the pump is in operation, pressure builds up that sucks up through the pipe. Placing a foot valve in the good pump extracts water from the underground well in one direction.
When the pump stops working, the pressure reduces. This way, the foot valve prevents any water remaining in the pipe from flowing back into the well. This principle makes the foot valve ideal for ponds, pools, and wells.

What is Foot Valve made From (With Foot Valve Diagram)?

Image Source: Google

Foot Valve Uses

The foot valve is valuable and applicable in several instances, which include;

• It is suitable in all kinds of pneumatic systems to prevent the pump column from draining when the pump is shut down.
• To maintain hydraulic pressure.
• Used in ponds, pools, and other scenarios where the pump is needed, such as lake pumps, deep well pumps, water/well pumps, etc.
• Useful in sump pumps which are applicable in industrial settings.
• Designed to keep the pump primed for a unidirectional flow of liquid.

How Does Foot Valve Works

As earlier stated, a foot valve allows for a unidirectional flow of liquids in a pipe without any reversal, which means it can be used to extract water from the well without a backflow. Let’s consider in-depth the foot valve working animation in pumping and water well.

• Firstly, the valve is mounted at the pick-up end of the piping, that is, the end that allows for water extraction.
• When operating the pump, it sucks water through the pipe. While at the same time, the valve opens, and water flows upward because of the pressure coming from the water.
• When the pump stops working, the upward pressure reduces or stops. The law of gravity takes effect, causing the remaining water to run down the pipe and back into the well. However, the foot valve comes into play, preventing the backflow of the water.
• The water in the pipe exerted much pressure on the foot valve. But because the valve is one-way directional, it doesn’t open at the other end. Instead, the pressure tightens the valve and prevents any reversal of water from the pump back into the well.

Why foot valve is used

A high-quality foot valve conserves energy and prevents well pumps from damaging, prolonging their lifespan. But a foot valve is recommended for any system requiring a one-way liquid flow. There are several situations where a foot valve is needed.
It’sIt’s best to use a high-standard foot valve, as it can be challenging to uninstall once mounted. In addition, a PVC foot valve is cost-effective and lightweight, but when high temperature or pressure is involved, metal valve option like stainless steel and bronze is preferred.

Foot valve for well pump: why you cannot just use a check valve

It’s crucial to note the difference between a check valve and a foot valve and why you can’t just use a check valve.

• With the multiple threads present on a check valve, it can be placed at the discharge side of the well pump line to discharge water, but a foot valve can only be placed at the bottom/end of the well pump for water intake to prevent backflow. This way, it prevents the pump from burning out and keeps it primed.
• Also, foot valves are useful on deep well applications to prevent loss of prime in the well piping system, but a check valve is mostly on the discharge side of the pump to prevent water from flowing backward.

Why foot valve is good for well pump

You might be questioning why foot valves are necessary for well pumping. Check out the reasons below;

• Foot valves come with a surge block, which exerts pressure on the valve body to remove residues and allow for easy water flow.
• A foot valve has a strainer attached to its inlet port to prevent dirt in the well from entering the valve and sticking to it.
• A foot valve has NPT connections with a filter attached to it, preventing the valve from clogging, preventing the well pump from being damaged.

How to Replace Foot Valve for Well

A faulty foot valve in your well causes the pump to lose its prime between cycles. Check out this guide below to help replace your foot valve;

• Disconnect the pump from the power source.
• Using an adjustable wrench, loosen the bolts at the top of your good seal.
• , detach the union fitting at the wellhead.
• Remove the pipe from the well and place it on a flat surface.
• Unscrew the valve and remove it from the bottom of the well.
• Clean the thread on the valve and apply a coat of thread sealant.
• Using the pipe wrench, tightly screw the foot valve onto the well.

Foot valve: best choice for a good pumping

As we wrap up, we will argue that the foot valve is the best choice for well pumping because of its many advantages. The internal balls allow quick sealing and valve reaction and flexibility to fit into all types of suitable pumps. This and many more benefits mentioned in this article make the foot valve a better option than other valves.

Foot valves are usually made from heavy-duty cast iron, stainless steel, plastics, PVC, and bronze. Since they’re used for water service purposes, these materials have a long-lasting effect even when immersed in water.

The post Check Valve vs. Foot Valve: Which is Better Valve Option for Well Pump appeared first on 91̽��.

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Valve Cv

What it is

The valve Cv demonstrates how much fluid or substance can pass through the valve under its extreme open conditions. Formally known as the valve flow coefficient, it is defined as the gallons per minute water volume that goes through the open valve at 1 pound-fore per square inch (PSI). Determining this coefficient is essential when selecting control valves.

Examples of valve Cv explained

To understand this technical concept better, you can refer to the example problem below.
Let’s say that you are using your industrial valve to control water flow, which has a specific gravity of 1. If its valve Cv is 1.00, this means that:

• It will allow 1 gallon per minute to pass through.
• It is under the pressure of 1 PSI.

Under the same specific gravity and pressure, the valve Cv should be 2.00 if you want it to have a flow rate of 2 gallons per minute. Overall, it shows that the valve Cv allows you to control your pipelines more precisely.

Valve Cv Formula

While you can find valve Cv calculators online, understanding its core formula is a better way to have a good grasp of the concept. The formula above consists of the following:

• Cv = valve flow coefficient
• Q = rate of flow
• SG = specific gravity
• ΔP = pressure drop

Note that you cannot use the valve flow coefficient formula if any of these components are undetermined.

Flashing & Cavitation, Valve Pressure Drop vs Flow Rate: Differences Among These Cv Factors

Viscosity correction factor

The standard valve Cv values on the market have water as the base fluid, but the valves can also be used in processing many other substances with varying viscosities. Fortunately, most manufacturing projects involve fluids whose viscosity differences can be ignored. If you require specific valves related to viscous conditions, you may refer to the correction factors below.

Image Source: Emerson

Rate of flow

The rate of flow is pretty intuitive with its name. Often represented in gallons per minute (GPM), this variable shows the amount of fluid going through the valve’s opening per set time. You can find it using the fluid volume and how long it takes for it to bypass the valve.

For example, you are processing two gallons of water. It took it 5 seconds to go through the valve. Hence, the rate of flow in GPM is 24.

Pressure drop

The pressure drop in PSI refers to the difference in pressure along a pipe due to the fluid’s friction against the tube. It is the hardest component to determine since it also considers the length of the pipe, the density of the fluid, diameter, and more. Referring to available charts from resource platforms like The Engineering Toolbox would be more straightforward.

How to Calculate Valve Flow Coefficient

Step 1: Determine the necessary numbers

To be able to use the valve flow coefficient formula, you must first find the numbers that you will substitute for the given variables. Determine the rate of flow, pressure drop, and specific gravity.
Example:

• Rate of flow (Q): 5 GPM
• Pressure drop (ΔP): 2 PSI
• Specific gravity: 1

Step 2: Replace the variables in the formula

Recall that the valve flow coefficient formula is Cv = Q * √(SG / ΔP). Plugging the numbers into the variables, we get: Cv = 5 * √(1 / 2).

Step 3: Calculate

This step involves basic arithmetic rules like PEMDAS. Below is a basic flow of the equation solution.

While the solution is straightforward with a clear set of rules according to the given formula, the first step of determining the correct numbers you need may pose some difficulty.

Cv Flow

Cv to GPM

While it’s more common for professionals to determine the valve flow coefficient for their pipes, converting the Cv to GPM may also be important to get the correct flow rate anticipated. Note that to find the GPM, you need these three values: Cv, ΔP, and SG.

Cv to Kv

Another concept related to the valve flow coefficient is the flow factor. The flow coefficient is an Imperial unit, while the flow factor is its equivalent in the metric system. There are two ways to convert between the two:

• From Cv to Kv = 0.865 * Cv
• From Kv to Cv = 1.156 * Kv

Cv to SCFM

Table from Cole-Parmer®

The standard cubic feet per minute value represents the flow capacity at precise air pressures, making it different from Cv, which applies to all pressures. Although uncommon, converting Cv to SCFM lets you know about more accurate calculations of a valve’s flow capacity. To get SCFM, simply divide the Cv by a factor that corresponds to specific air pressures in PSI.

Cv Practice Problem

Here’s another example of determining the correct valve flow coefficient that you need for your project.

Valve Cv Circulations

Control valve Cv circulation with chart

Image Source: Learning Instrumentation And Control Engineering

While the valve flow coefficient is calculated at the fully opened state of a valve, it can also be configured to more specific valve travels (or valve openings). The table above shows the relationship between the Cv and the opening percentage of the control valve.

Ball valve Cv circulation with chart

Image Source: Valmatic

This table demonstrates the rate of valve opening according to the rotation of the shaft. It also represents the control precision differences between ball valves and globe valves.

Globe valve Cv circulation with chart

Image Source: Applied Flow Technology

Controlling the flow rate involves the valve’s opening level and its equivalent valve Cv. This chart presents the characteristic curves of various types of valves like globe valves, ball valves, and more, which may give insight into the precision of control depending on the valve type.

Check valve Cv circulation with chart

Image Source: Hansen Products (NZ) Limited

Notice that the table above details the GPM, Kv value, Cv value, and pressure drop of the check valve in several parts. These are all data that were determined using the given formulas we’ve discussed.

Butterfly valve Cv circulation with chart

Image Source: Kimray

This table demonstrates the difference between a 2” and 3” butterfly valve. As displayed, the maximum Cv’s reached under their fully open states are 47 and 117, respectively.

Gate valve Cv circulation with chart

Image Source: Industrial Controls

This table shows the various trends between the maximum flow and valve travel of different valve types.

Needle valve Cv circulation with chart

Image Source: Advance Electric Co., Inc.

For this table, the flow rate is evaluated against the number of turns at various values of pressure drops.

Conclusion

To grasp the most suitable valve size for your pipes, considering the valve flow coefficient or valve Cv is essential. This allows you to achieve the appropriate flow capacity that you want for your projects, and it can even provide you with finer control over your flow rate. If you are looking for quality industrial valves, visit 91̽�� today.

The post Valve Cv Circulation: What It Is and How to Calculate It appeared first on 91̽��.

Differences Between the Trunnion and Floating Ball Valve

Source: adamant-valves.com

A trunnion ball valve consists of a ball mounted on a trunnion on the bottom and joined to a stem at the top. These parts are often welded together which is why this type of valve is sometimes referred to as a trunnion mounted ball valve or a fully welded trunnion ball valve. Given as the ball is mounted and experiences less friction and media pressure force, this valve requires less torque to operate.

A floating ball valve, on the other hand, comprises a ball linked to a stem at the top but floats freely at the bottom. It is held in place by fluid pressure and seat rings as opposed to being mounted on a trunnion. As such, it requires high torque to operate. It is, nevertheless, a reliable bi-directional shut-off valve.

How Does a Trunnion Ball Valve Work

A trunnion ball valve consist of 4 main parts:

An actuator lever

A stem

A ball

A trunnion

The trunnion forms the base onto which the ball is mounted. At the top end, the ball is linked to the stem and the stem is connected to an exterior actuator lever. In a flanged trunnion ball valve, there are spring-loaded seats and a polymer ring insert between the trunnion and the ball. The springs put pressure on the ball to keep it in place. Together with the polymer ring, they also reduce friction when the ball is rotating.

To facilitate the flow of media, the ball is made hollow in the middle. It can either be a full bore or a partial bore. A full bore is a ball whose hollow part is the same size as the pipeline it is installed in. Whereas in a partial bore, the diameter of the ball’s hollow part is smaller than the diameter of the pipeline.

When the actuator is turned, the stem connected to it also turns. These actions cause the ball to rotate on the trunnion to an open or closed position. During and after fluid flow, seals in the seats and stem prevent the fluid from leaking out of the pipeline. An adjustable box also helps the valve take on different capacities of pressure. A typical trunnion ball valve would also have 2 bleeders for purposes of depressurization.

The structure of a trunnion ball valve makes it ideal for application in high pressure and high-temperature fluid management applications.

Pros and Cons of a Trunnion ball valve

Source: Pixabay

Pros:

It requires less torque to operate

It can be applied in both large scale or small scale operations

Less friction during trunnion ball valve operation helps mitigate wear and tear

Provides full-proof sealing

Cons:

Due to the fully-welded or bolted-together design of a trunnion ball valve, it is difficult to repair it in-line. Repairs would thus interrupt normal pipeline operations.

If maintenance is not carried out as required, welded parts could begin to operate with higher friction which could lessen efficiency.

Applications of Trunnion Ball Valve

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Due to its resilience, a trunnion ball valve can be applied in a wide range of applications including:

Chemical manufacturing plants – the transmission of chemicals through pipelines during production requires stringent management. More so where corrosive chemicals are involved because leakages and high reactive temperatures could harm staff or the surrounding environment. The full-proof sealing added to trunnion ball valves during manufacturing and their high-temperature resilience makes them ideal for the safe management of such fluids.

Petroleum industry applications – trunnion ball valves manufactured to are recommended for petrochemical industry applications because they are leak-proof and can handle high pressure. These features are especially useful in high-volume petrochemical pipelines and gas lines which require careful pressure management.

Power generation- power is generated using different fuels. Geothermal power, for example, is generated using steam while hydropower relies on water. In each case, the medium used to generate power needs to be released into the system in measured units. A trunnion ball valve is suitable for controlling the flow of such media as It can keep up with the large-scale, high temperatures, and high-pressure nature of such operations.

How Does a Floating Ball Valve Work

A floating ball valve comprises 3 main parts:

An actuator lever

A stem

A floating ball

The actuator lever is the outermost part used to open or shut-off fluid flow. When it is turned within a 90-degree angle, it rotates the stem which turns the ball to an open or closed position.��

At the base of the valve, the ball remains unmounted and is only supported by a stationary polymer ring and seats.

When the valve is shut, medium pressure pushes the ball firmly against the seats. This provides a tight seal and stops flow immediately. However, given as the ball is unsupported, high levels of pressure can not be distributed to a base to lessen the force on the ball. A floating ball valve is thus only recommended for low to medium pressure applications with average temperatures. Where necessary, it can also be customized to work in .

Regarding overflow management and controlling leakages, a quality floating ball valve should have an anti-static and anti-blow out stem design. This means that in instances when pressure is elevated or during fluid surges, the stem would remain in place with no leakages. A flexible soft seat is equally essential as it creates sealing around the floating ball to stop media flow.

Pros and Cons of a Floating Ball Valve

Source: Pixabay

Pros

A floating ball provides impenetrable sealing when pushed onto its seats.

It responds fast to shutting off or allowing fluid flow.

It is very efficient in small scale applications for which other valves would be unsuitable due to size.

Cons

It is limited to small designs to manage torque levels. The

It operates at high torque.

The high pressure experienced by seats and seals during shut off can increase their rate of wear and tear.

Applications of a Floating Ball Valve

Source: Pexels

The efficiency of floating ball valves makes them ideal for applications such as:

Emergency shut-off systems- pipeline systems such as those involving fuels, water, or critical gases often require a fast-responding shut-off valve in case of emergencies. Given as this type of ball valve is unmounted, it works fast and is therefore suitable for SIL 3 emergency shut-offs.

Water systems- water distribution systems require that pressure is maintained at optimum levels to sustain flow and prevent air pockets from restricting the flow of water. The flow of water also needs to be controlled to prevent overflows. A floating ball valve would be a good choice for water system control as it is pressure-sensitive and can open and shut as needed based on pressure conditions.

Pipeline pressure relief– is essential to avoid busts and similar mishaps. A floating ball valve can be added in a pipeline as a pressure outlet valve as it takes on the pressure while remaining intact as opposed to a mounted ball valve that could sometimes blow out.

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Two of the most common valves used in industrial applications are ball valves and gate valves. Both are known to provide tight shut-off mechanisms. This article will compare the two valves in various factors such as working mechanisms, designs, ports, and the likes.

What is a Ball Valve?

The ball valve is part of the quarter-turn valve family. It only takes a 90-degree turn for it to open or close. The ball valve design has a hollowed-out ball that acts as the disc which allows the flow of media. Mostly for non-slurry applications, ball valves are also suited for applications that require tight shut-off.��

The quick opening and closing of the ball make it important in some applications that need media isolation. Ball valves are commonly used in low-pressure applications. In a nutshell, ball valves are best for control and management of media with minimal pressure drop.

What is a Gate Valve?��

On the other hand, gate valves belong to the linear motion valve family. Otherwise known as the knife valve or the slide valve, the gate valve has a flat or wedge disc that acts as a gate. This gate or disc controls the flow of fluid inside the valve. The gate valve is best used when the linear flow of media with less pressure drop is preferred.

It is a shut-off valve with throttling capacity. It is intended more for material flow as to flow regulation.�� More suitable for thicker flow media, the flat disc of gate valves makes it easier to cut through such kind of media.��

The gate valve is also part of the rotary family as the wheel or actuator needs to be rotated for the wedge or disc to open. For its closing position, the gate moves downwards and between two seats located on the upper portion of the disc as well as at its bottom as shown in the image above.��

Gate Valve vs. Ball Valve: Working Mechanism

How Does a Ball Valve Work?

Ball valves have a hollow sphere that allows the passage of media. If you look at the cross-section of the ball valve below, the operation is through the rotation of the shaft or stem by a quarter of a turn. The stem is perpendicular to the ball part of the valve.

Fluid is allowed to pass when the stem is at the right angle with regards to the ball disc. The lateral movement of the media plays an important role in the shut-off mechanism. Ball valves use fluid pressure to act upon the valve or seat to provide a tight seal, depending on the ball valve configuration.��

Ball valves can be full port or reduced port. A full port ball valve means its diameter is the same as the pipe. This allows for low operating torque and pressure drop. However, there are also reduced port type where the size of the valve is one size smaller than that of the pipe size.��

How Does a Gate Valve Work?

Gate valves work by lifting the gate or disc to allow the media to pass through the valve. These types of valves only allow unidirectional flow with little pressure drop. You would often see gate valves with handwheels. The handwheel is attached to the packing.��

There are two kinds of gate valve stem designs. When this hand wheel rotates, the stem rises to the outside environment and, at the same time, lifts the gate. The other kind of gate valve is the non-rising gate valve. This is characterized by the stem threaded into the wedge, thereby exposing it to the media.��

When the gate valve opens, the path becomes larger. The flow path is not linear in the sense that the media can occupy the void as seen in the illustration below. If the gate valve is used as a throttle, it would have an uneven flow rate. This will cause vibration. Such vibration can cause damage to the disk.

Valve Flow Direction

Ball valves and gate valves, by convention, is bi-directional. This means that ball valves have the capacity to block the media from both the upstream end and the downstream end. Check the illustration below.

Valve Seal Capacity

For the ball valves, the seals can be fixed for the floating ball valve design and it can be floating for the trunnion-mounted ball valve. Since ball valves are often used in low-pressure applications, considering the nature of its working mechanism, the primary seals are often made of PTFE and other related materials.��

While the quick closing and opening of the ball valve can be advantageous, this can also cause some problems. Ball valves are prone to or the sudden surge of pressure upon closing of the valve. This condition damages the seats of the ball valve.��

Furthermore, water hammer can increase the pressure inside the ball valve. In applications where such conditions can occur, i.e. combustible material, there is an emergency seat seal, often made of metal. This is the second barrier in conditions where the elastomeric seal becomes damaged in high-pressure services. To relieve pressure, ball valves can have a pressure vent installed.

Gate valves minimize pressure drops when fully opened. This is through the use of full bore port design. This means that the size of the valve is equal to the size of the pipe. It is because of this characteristic of gate valves that give them an advantage over ball valves. Water hammering does not occur in gate valves.

The downside of the gate valve is, high-pressure differential often happens in the shutoff. The friction can cause seat and disk wear.��

Valve Design and Construction Differences

The main difference between ball valves and gate valves is their structure even if they function similarly.

For ball valves, movement of media is free-flowing. Aside from this, the ball valve design allows it to last longer even after heavy use. Of course, one should also take into consideration the type of material being used to manufacture it.

While ball valves do not provide fine control, their tight shut capability is one of the best for low-pressure applications. Ball valves are reliable in this aspect. Low-pressure loss is another of quality of ball valves. However, because of the quarter-turn capability of ball valves, it takes up more space.

Gate valve, on the other hand, uses a handwheel to open or close the disc. The valve body is also much more slender, thus, only a narrow space is needed. In contrast to ball valves, gate valves, offer a more refined control as it has throttling abilities. It may not have a quick shut off and on capability, but it can control not only the media flow but also its pressure.��

Valve Material

Ball Valves:

• – Stainless steel ball valve��
• – Brass ball valve��
• – Bronze
• – Chrome
• – Titanium
• – PVC (Polyvinyl chloride)
• – CPVC (Chlorinated polyvinyl chloride)

Gate Valves:

• – Cast Iron gate valve��
• – Cast Carbon Steel
• – Ductile Iron gate valve��
• – Gunmetal Stainless Steel
• – Alloy Steel
• – Forged steel gate valve��

Application

Ball valves are often used in applications that require a smaller diameter, which can be up to DN 300 or a 12-inch diameter pipe. On the other hand, gate valves are often used in applications that require noncritical services and leakages are not a top priority.��

Gate Valve

• – Oil and Gas Industry
• – Pharmaceutical Industry
• – Manufacturing Industry
• – Automotive Industry
• – Marine Industry

Ball�� Valve:

• – Ball valve for gas Industry
• – On/Off Shore Petrochemical Industry

In Summary

Ball valves have its advantages and disadvantages and so are gate valves. Understanding how each function and knowing whether such valve suits the application should be the priority. Contact us and we will give you a free valve estimate.

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(2) Classifications of pneumatic ball valves
According to the material, pneumatic ball valves can be divided into stainless steel pneumatic ball valves, plastic pneumatic ball valves, sanitary pneumatic ball valves, carbon steel pneumatic ball valves, cast iron pneumatic ball valves, etc.

According to the connection mode, pneumatic ball valves can be divided into pneumatic flanged ball valves, screw thread pneumatic ball valves, welded pneumatic valves, etc.

According to pressure, pneumatic ball valves can be divided into low pressure pneumatic ball valves, middle pressure pneumatic ball valves and high pressure pneumatic ball valves.

According to the channel position, pneumatic ball valves can be divided into throughway pneumatic ball valves, three way pneumatic ball valves and right-angle pneumatic ball valves.

According to characteristics of the ball, pneumatic ball valves can be divided into floating ball valves and trunnion ball valves.

Floating ball
The ball of the floating ball valve is floating. Under the effects of medium pressure, the ball will shift and be tightly pressed on the sealing surface of the outlet end to ensure the sealing performance of the outlet end.

Fixed ball
The ball of the trunnion ball valve is fixed, and it will not shift after being pressed. All the trunnion ball valves are with the floating valve seat. Under the effects of medium pressure, the valve starts moving to make the sealing ring pressed on the ball so as to guarantee the sealing performance.

(3) Electric ball valves
The electric ball valve is composed of the actuator and the ball valve. It is a kind of device which is used for the pipelines in the industrial automation and process control. To be specific, it is generally utilized for the remote on-off control of the pipelines’ media.

According to the definition of the electric ball valve in the “Glossary of terms for valves”, the electric ball valve is a kind of valve whose discs (balls) are driven by the valve stem, and then rotate around the axis of the valve. Electric ball valves are mainly used in cutting off and getting through media, or utilized for regualting and controlling media in the pipelines. As for the hard sealed V-shaped ball valve, there is a strong shear force between the V-shaped ball and the metal valve seat made of overlaying cemented carbide.

(4) Comparisons between pneumatic ball valves and electric ball valves
Cost
The pneumatic ball valve has heavy load, but is cheaper than the electric ball valve. Thus, using pneumatic ball valves can reduce engineering cost.

Operational safety
Users who utilize the pneumatic ball valve can switch on or off the valve. When the electric ball valve has no power, it can only stay in its place, which presents that the pneumatic ball valve has great advantages on safety. Because when the electric ball valve is out of power, it will close so as to avoid the filter’s backset and spillover. The pneumatic ball valve does not need electricity, whereas the electric ball valve uses 220V or three phase of 460V. So to say, the electric ball valve is more dangerous in a damp environment, whereas the pneumatic ball valve is not affected by the damp environment. About maintenance, it is easy to maintain the pneumatic ball valve because there is only one moving part. The electric actuator of the electric ball valve needs to be maintained by professionals due to more parts of the electric actuator.

Performance
The pneumatic ball valve can adapt to frequent full load. The electric ball valve is limited by the load capacity of motors and maximal start-up times per hour.

Life cycles
The pneumatic ball valve has the long life cycle with about 2 million��actions. The repeatable usage rate of the pneumatic ball valve can be controlled accurately, which can almost reach 0.25%.

Corrosion resistance
The pneumatic ball valve with epoxy coating inside and outside the pneumatic actuator has great adaptability to the work environment. It can adapt to bad work environment such as flammable, explosive, dusty, ferromagnetic, radioactive, vibratory environment, etc.

Others aspects
When the pneumatic ball valve is not working properly, it can be repaired or replaced without power or air sources. About maintenance, the pneumatic ball valve does not need oil, whereas the electric ball valve need a large amount of oil. About manual operation, the pneumatic ball valve can be operated without power. About speed, the pneumatic ball valve works and responses quickly so as to adjust accordingly. The speed of the electric ball valve is constant and can not be changed.

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