An integral part of any pipeline is a shut-off valve, with which you can regulate the pressure of the transported flow, up to its complete shutdown. Many manufacturers have their own designs used in the manufacture of such parts, but they are all based on generally accepted designs. This article discusses this type shut-off valves, How ball valve, its advantages, disadvantages and material of manufacture, as well as its comparison with other cranes.

1. According to the installation method, there are welded, flanged and threaded valves. Each one is designed for a different purpose, ball valves with welded joint have a body elongated on both sides, this is done so that during welding, vulnerable elements do not burn out from high temperature. Cranes with threaded assembly unlike welded ones, they are serviceable and can be replaced at the end of their service life. The valve with a flange is considered the easiest to install and maintain; it has a connection corresponding to the main pipe, which is bolted together and sealed with paronite or rubber gasket. It is necessary to follow the rules for installing the product, for example, when welding a faucet, you must not allow scale to get on the polished sphere, otherwise the surface will become uneven and when turning the ball will leave notches on the gasket, which will lead to loss of tightness.
2. Available by type of shut-off valves Ball Valves, with floating or fixed rotary part. The ball without support is located inside a special polyelite seal, which securely fixes it and forms a sealed rotating unit. A ball element fixed on both sides is more reliable during operation, since due to the support bolts it is able to withstand the loads of the internal environment.
3. According to the manufacturing and repair method, there are cast, maintenance-free and dismountable products, with the possibility of replacing worn parts. Repaired faucets are a little more expensive than others; they have an upper inspection cover for disassembling and diagnosing internal elements or are completely disassembled into several parts.
4. Valves are divided, depending on the type of control, into mechanical, hydraulic and electrically driven valves. The steering wheel or ball foot is rotated manually, using hydraulic press or remotely using electric motor, which are most often found on pipelines large diameters and in hard to reach places, where it is not possible to perform operations to adjust the tap manually. If the size of the sphere does not allow turning in one step, a gearbox with a worm gear is installed on the control element, which transmits the force to the locking mechanism.
5. According to the degree of maneuverability, cranes are divided into standard, full bore and not full bore. Inner ball in standard version has a cross-section slightly smaller than the main line, so the volume of medium flow is about 80-90 percent. In a full bore ball valve, the shut-off element matches the diameter of the pipe and the conveyed flow does not encounter any resistance. For pipelines where flow narrowing is required, non-full bore ball valves are used.

Gate valves with a ball-shaped locking element are made of various metal alloys, depending on the purpose. They are mainly used in water supply systems, gas mains, and pipelines for transporting chemical derivatives. Ball valves are resistant to impact high temperatures, therefore suitable for installation in heating systems, heating mains and heat supply units apartment buildings. Modern manufacturers produce shut-off valves of the same length as the clamping flanged valves with gland packing, which makes it possible to quickly replace outdated equipment with new equipment without adjusting and joining pipes.

Also, depending on the number of branch pipes, valves are multi-way, three-way, straight-through and angular. Their design is not particularly different; they differ in the number of connected pipeline branches and the method of flow control.

The valve operates in several stages. When the control lever is turned perpendicular to the pipeline, the non-passing part of the ball blocks the pipeline, preventing the transported flow from moving further. The tightness is ensured by the sealing ring in which the ball is located. If the control lever is turned along the pipeline, then the valve is turned with an opening in the direction of movement and the internal medium is freely directed along the body of the valve.

It is worth noting that to limit the volume of incoming liquid inside the pipe and regulate pressure, only a ball valve with a plug operating principle is suitable, since a disc valve will not be able to regulate the flow, and a spherical valve, open halfway, will quickly wear out. The cork stopper consists of two locking elements, with a separate control lever for each of them. When turned, one element narrows the diameter of the valve and limits the flow of liquid, the second has a spherical shape and completely blocks the flow of the transported medium.

Advantages and disadvantages of ball valves

Compared to similar products, ball valves have many advantages:

1. Small dimensions compared to pressure or wedge-shaped dampers.
2. Wide range of installation methods depending on technical conditions.
3. The internal elements of the taps are made of stainless metal, which extends the life of the product.
4. After installation, no further maintenance of the damper is required; all gaskets are located inside the body and there is no need to change the stuffing box packings.
5. Compared to pressure-type valves, ball valves weigh less, which makes the overall design lighter.
6. Easy to operate. Thanks to the feature of the ball, locking occurs when the lever rotates 90 degrees, which is much more convenient and faster than using a rotary wheel.
7. If the valve is made of a prefabricated body, if the internal element fails, it can be replaced without removing the valve from the main line.
8. Possibility of installation in vertical or horizontal position with the control placed on the top or side.

But along with the advantages, ball valves also have several disadvantages:

1. During operation, sand and dirt particles fall on non-metallic parts and seals, subjecting them to wear and deformation, which ultimately leads to loose flow closure. It is not possible to replace such an element; the shut-off valves will have to be replaced completely.
2. For rare use, when the faucet for a long time is in open position, the metal ball “sticks” and when turning, the control lever can be torn off.
3. Adjustment of flow volume and pressure is possible only with one type of ball valves; other types of shut-off valves are not full opening quickly fail.
4. Ball valves without stop pins may break off from the upper leg due to frequent use and the device will have to be replaced.
5. The cost of spherical products is slightly higher than comparable analogues.

The difference between ball valves and other types of shut-off valves

Cranes, inner part which are made in the form of a sphere, differ from hose, retractable or wedge-shaped products in their design. In valves with a hose valve, the movement occurs inside the resonant tunnel, which must be pressed to close, which is not entirely practical, since the hose may burst if exposed to excessive pressure. In a ball valve, the fittings through the passage are metal; they are not afraid of pressure and temperature surges.

The ball mechanism differs from the retractable and wedge-shaped mechanism in the position of the rotating part. For the former, it is located above the valve body, which increases the construction size, while for a spherical device, the entire locking part is located inside the valve itself.

Although many manufacturers are trying to produce shut-off valves of the same construction size, like analogues, the height of the pressure tap, due to the design feature, is slightly higher, which affects under cramped installation conditions. Also, the weight of the ball valve is much less, and therefore the load on the pipeline will be low.

In the event that emergency locking of the pipeline is required, in the event of an accident and repair work, it will be easier and faster to perform these actions using the ball valve lever, since the movement of the mechanism is only 90 degrees. All seals of the spherical device are made of rubber or polyethane, and in similar products with a clamping mechanism, tightness is ensured by an stuffing box, which, for normal functioning The unit must be periodically inspected and replaced with a new one when worn out.

Thus, we can conclude that the ball valve is in many ways superior in quality and ease of maintenance to similar parts with other locking mechanisms. Technologies for manufacturing and designing such products are constantly being improved and improved, the materials used and the improving functions of shut-off valves are changing.

The most popular structures today are taps and valves. Many do not understand the differences between these two types of shut-off valves and are guided by the advice of sellers and friends. Sometimes you can even see the influence of fashion. For example, 10 years ago everyone switched from valves to taps, but now it’s the other way around. However, both of these types of fittings have their own individual characteristics.

Gate valve

The operation of the valve is to block the flow of liquid or gas with a locking element. The overlap is made perpendicular to the flow.

The design of the valves is simple, and they themselves are quite unpretentious in operation. Valves in open form have a small hydraulic resistance. The valve works perfectly with viscous media, passing it in all directions. One of the most popular brands of valves is AVK (avk official website Russia).

Now about the cons. It is difficult to regulate the flow with a valve. The locking element has only two positions. Either closed or open. For aging high pressure the reinforcement must be strong and massive. The locking element wears out over the years, and its repair is very difficult and often requires a complete replacement.

The valves are:

• Wedges. Its sealing surfaces are at an angle to each other, which ensures good contact regardless of temperature and even corrosion.
• Parallel. Here, accordingly, the sealing rings run parallel. They are used where there is no need for 100% tightness.

Cranes

The closing part of the faucet is made in the form of a rotating element with a hole through which the medium passes. Valves are available in conical, ball and cylindrical types. Today the ball valve is considered the most popular. Turning the plug can regulate the supply of medium from reducing the flow to completely blocking it.

The taps can operate with both liquid and gas. Unlike gate valves, they are more compact.

The weak point of any faucet is the seals, which, when worn, destroy the entire seal. Also, due to non-metallic seals, the faucet cannot withstand various aggressive environments.

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Comparative characteristics of shut-off valves

General characteristics of different types of shut-off valves

Shut-off valves are used in the installation of gas pipelines and sewer systems. It can be seen on pipelines general purpose, industrial type, industrial pipelines with special conditions work, plumbing pipelines and many others. They are designed to block any water or gas flows.

For these purposes, a gate valve, tap, valve, valve, as well as other locking mechanisms are used. Household plumbing cannot do without such mechanisms, but few people understand the difference between a faucet and a valve. Without this it is simply impossible to connect household appliances, fix the leak, turn off the gas or change the mixer. Plumbing surrounds us all around us, and shut-off valves are an integral part of it.

In fact, it has significant differences, both design and operational, although any constructive solution This type of valve always works in two positions: closed and open.

But, based on their functional characteristics and scope of application, one or another type of device is selected. For the right choice you should know how the principle of their operation may differ, and what function each of them performs.

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Operating principles of taps, valves and gate valves

Design solutions for shut-off valves are taps, valves and gate valves. How are they different from each other?

Gate valves are the most common and most popular locking devices. Their design implies that the locking element is in the closed and open position. The flow of the working medium is blocked due to the fact that the locking element moves perpendicular to its axis. Gate valves can be used exclusively as locking valves. They are parallel, wedge and gate.

A valve or valve is capable of blocking the flow of the working medium due to the fact that the device moves parallel to the axis of its movement. It, unlike valves, can be used not only as a shut-off device, but also as a regulating device due to the fact that its design will allow you not to completely block the flow of the medium, but partially.

A significant drawback is the valve’s inability to respond to changing speed and pressure in the system. Therefore, its scope of application is pipelines with a relatively constant flow and pressure of the working medium. In addition to regulating and shut-off devices, there are bypass, mixing, and distribution structures these mechanisms.

A faucet is another type of shut-off valve. It can be used as a shut-off or a regulating device. It functions like this: the locking element, rotating around its axis, moves in a direction perpendicular to the movement of the medium flow. The locking element has the shape of a disk. Due to its rotation around its own axis, the liquid overlaps in a perpendicular direction.

Modern plumbing offers various structural solutions shut-off valves that have own characteristics. Of course, this entails the presence of distinctive advantages and disadvantages, which manifest themselves in different conditions. Therefore, in order to choose the right shut-off valves, it is necessary to take into account the design features of the pipeline, as well as the conditions of use and requirements for a specific device. To do this, you need to understand the difference between, for example, a faucet and a valve, because the difference between them is not so obvious.

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Comparative characteristics of tap and valve

The main difference between a faucet and a valve is the adjustment of the pressure of the working medium. The valve can make such adjustments, but the faucet cannot. Moreover, taking into account the operating rules of taps, it is strictly prohibited to regulate the pressure using them. The tap has only two functions: open and close the flow of the medium. But the valve can easily regulate the pressure of liquid or gas.

This difference is due to design. The shut-off element in this device moves in the direction of flow and eventually sits on the seat. In cranes, it rotates around its axis. In addition, there are ball valves. In their design, the shut-off element is a ball that rotates perpendicular to the flow, as a result of which the diameter of the pipe changes. But the valves are equipped with a ground axle box. This design solution implies that by moving the axlebox rod, the valve, which is attached to the rod, is raised or lowered. Thus, the opening or closing of the hole located in the seat occurs.

Visually, it is easy to distinguish a valve from a faucet. If the shut-off valve has a simple handle, and the end of this handle is attached to the stem, then it is a faucet. If there is a thumb in place of the handle on the rod, it is a valve.

In water and gas pipelines you cannot do without a device called a valve. A valve is a device designed to shut off the supply of various liquids and gases. However, shutting off the water supply is not the main purpose of the product in question. It can also be used to regulate the pressure of water or gas supply through a pipeline, and can also be used as a safety device and condensate drain.

Device design

The valve design is quite simple, and the product consists of the following main parts:

1. Frame.
2. Locking device.
3. Handwheel or locking handle.

The body of the product is made by casting. A locking device is installed inside the housing, and the flywheel is brought out. The body also has threads on both sides, through which the valve is connected to the water supply or gas pipeline. The cross-sectional diagram of shut-off valves is as follows:

Product classification

The water valve is classified according to a number of different characteristics, which include:

1. Type and design locking device.
2. Material of manufacture.
3. Features of connection with water or gas pipelines.

Based on the type and design of the locking device, valves are divided into the following types:

• Valve
• Cork or cone.
• Ball.

Let's find out the main features of each type of valve, and also determine their purpose.

Valve devices

The valve valve is also called a valve tap, since the body of the product is divided into two parts by horizontal and inclined partitions. The design of the product with an inclined partition has a hole that has a groove for the valve. This hole is called a saddle.

The valve is part of the rod, which is located at the bottom of the product. An elastic gasket is inserted into the design of the product, resting against the saddle. By means of this stop in the seat, the supply of fluid flowing through the device is blocked. At the top, the rod is equipped with a thread that connects to the threaded connection of the seat nut. With this threaded connection the valve is raised and lowered, thereby shutting off and regulating the pressure of the supply fluid.

Products of this type have advantages and disadvantages. The advantages include:

1. Withstand high pressure.
2. Adjustment of water volume and pressure.
3. Easy to operate.
4. If the locking device fails, it can be replaced.

The disadvantages of such a device are:

1. High rate of abrasion of the gasket, since with frequent opening and closing of the device, contact of rubber with metal occurs.
2. Relatively short service life.
3. To completely shut off the liquid supply, you need to rotate the flywheel for a long time.

Cone type product

A cone valve is a type of valve product. The differences between the two devices lie in the design of the locking mechanism. If in the previous version the locking mechanism is presented in the form of a partition, then in this design the device has a plug in the form of a cone. When the rod rotates, it lowers shut-off valve into the opening of the partition, thereby stopping the flow of liquid.

The advantages and disadvantages of this type of product are similar to those of a valve type valve. The cone valve has the following structure as shown below.

Ball type device

The operating principle of this type of valve is completely different from the functioning of previous options. If previous products provide shutoff of water perpendicular to the pipeline, then with a ball-type device everything is different.

The main locking device is a ball, which has a through slot proportional to the fluid flow. Shutting off the liquid supply is ensured by moving the ball with the slot to a perpendicular position. Such valves are also called gate valves.

The advantages of such products include:

1. Simplicity of design, which allows the device to be used for a long time.
2. Tightness of the structure. Only the stop ball is in contact with water, which also affects long term product services.
3. Shutting off and opening the liquid supply is done by turning the handle 90 degrees or half a turn. Due to the rapid shut-off of the liquid supply, such devices are also called reversible floors.

As practice shows, the quality of valve production plays a significant role in the service life. Water valves European production have a service life of up to 10 years, while cheap Chinese analogues fail after a few years.

The disadvantages of the types of valves under consideration include:

1. Inability to repair a water supply ball valve. In Chinese products, the integrity of the connection between the handle and the locking ball is compromised. This causes the handle to continue to rotate and the ball to remain in place in a stuck position.
2. Inability to regulate fluid flow. It is possible to regulate the flow of liquid using such a product, but in this case the manufacturers do not guarantee the long service life of the device.

What is the difference between a valve and a faucet?

The difference is not in the type of valves, as many people, even plumbers, are accustomed to thinking. Taps and valves are different, although they are often called by the same name. This difference lies in the design of the housing. If the valve is intended to be installed at the junction of two pipes in order to, if necessary, shut off the liquid supply, then the tap is located at the end of the pipeline. A tap is a kind of limit switch that serves to supply water when the need arises.

Now you need to find out what is the difference between a valve and a gate valve. Many people believe that there is no difference between a valve and a valve, however, this is not true. What a valve is and why it is needed is already known. Now let's analyze the valve to find out its main differences from the valve.

The valve performs similar tasks as the devices discussed in the material. However, the valve is not able to regulate the flow rate, so it only closes and opens the flow. The valve cannot regulate the liquid pressure due to its design features. The damper in such a device moves only up and down. The difference between a gate valve and a valve can be seen clearly in the photo below.

What are locking devices made of?

Before you find out what valves are made of, you need to divide them into two types:

• installed in internal water supply networks;
• mounted on external water and gas pipelines.

If the product is intended for internal networks water supply, then devices made of brass, bronze, of stainless steel and plastic. If the products are used for outdoor work, then the above materials are used, as well as additionally steel and cast iron.

1. Plumbing fixtures made of brass and bronze are expensive options. However, their cost is justified by quality and durability. Such devices have light weight, small dimensions, and can also be installed not only on the water supply system for supplying cold water, but also hot. Such products are also used in heating systems, since scale does not settle on their surfaces.
2. Stainless steel valves. Another a good option, which has a long service life. They are several times cheaper than brass and bronze devices.
3. Plastic products are among the cheapest, but they are in no way inferior in quality to the above models. Their disadvantage is that they can only be installed in plastic pipelines.

Cast iron and steel valves are popular for installation on external pipelines. For the manufacture of such products, cast iron and steel are used, which will significantly reduce the price of the device. After all, similar products made of brass and bronze will cost tens of times more.

Connecting devices to pipes

Valves are divided into two types according to the installation method:

1. Coupled and threaded. Main connecting element with this connection method it is a thread. It can be internal and external on the valve (popularly called “mother-father”). Fittings of this type are installed in pipelines with a pressure of no more than 1.6 MPa.
2. Flanged. At the end parts of the pipes there are flanges, with the help of which cast iron or steel products are connected. Installation of such devices is carried out on main and industrial pipelines in which the water pressure exceeds 10 MPa.

Plastic valves are connected to pipelines through special welding. Knowing the features of the devices in question, you can select best option for appropriate installation. IN Lately Ball valves are widely popular because they have a long service life, despite the inability to repair them.