What are shut-off control valves

Shut-off and control valves. Operating principle

Shut-off and control valves are used to control the flow of media at industrial production facilities and household life systems. Trunk pipelines, oil and gas fields and their processing plants, steelmaking and chemical plants, wastewater treatment plants and city water supply are just a small part of the enterprises that require a huge amount of shut-off and control valves.

There are many types and modifications of shut-off and control valves. We will look at the operating principles of the most common product types such as ball valves, butterfly valves, gate valves, gate valves and diaphragm valves.

The operating principle of all the above types of shut-off valves is approximately the same. All these devices either limit the flow of the medium (air, liquids, steam, gas, solids) or completely block it. The only difference is in the design elements of the types of shut-off valves (membrane, disk, ball) with the help of which the flow is blocked.

Operating principle of a ball valve

The ball valve is one of the most reliable elements of shut-off valves. Valves of this type provide a very good possibility of completely shutting off the flow if the shut-off element is turned a quarter turn (90°). The advantages of the ball valve also include low closing time and low probability of leakage in case of seal wear

Ball valves can be divided into partial bore and full bore. A partial bore valve in the open state has a passage diameter smaller than the diameter of the pipeline, a full bore valve has a passage diameter equal to the diameter of the pipeline. A full bore ball valve is more efficient because... allows the pressure drop across the valve to be minimized.

Ball valves are only recommended for use in the fully open or fully closed position. They are not designed for precise flow control, or for operating in a partially open position, as this would create excessive pressure on part of the housing, which could lead to its deformation. Deformation of the housing leads to leaks and breakdowns.

Operating principle of a butterfly valve

In the "open" position

Step 1

Step 2

In the "closed" position

A butterfly valve regulates the flow using a special element - a disk mounted on a shaft and rotating around its axis. Just like a ball valve, a butterfly valve is capable of closing in a fairly short time, since the disk makes the same 90 ° rotation, which is why this valve is also called a quarter-turn.

Depending on the position of the disk and shaft relative to the body, butterfly valves can be three-eccentric or two-eccentric. A valve with offset eccentricity means that the axis of the disk is shifted relative to the geometric axis of the body, which ensures a tighter fit of the disk to the valve seal, and therefore eliminates leaks.

Butterfly valves are characterized by simplicity of design, light weight, and compact dimensions. But the materials used in the manufacture of valves may limit their use in very high temperatures or extremely aggressive environments. This mainly concerns valve seals made of polymer materials.

Operating principle of a shut-off valve

In the "open" position

Step 1

Step 2

In the "Closed" position

The shut-off and control valve is suitable for use at various technological facilities, excluding only large-diameter pipelines , to control and regulate the flow of the medium.

The principle of operation of valves is not very different from the principle of operation of other shut-off and control valves. The advantages of these valves are that the valve stroke is short for full opening; accordingly, such a valve usually has small dimensions and an acceptable weight. The valve also has high tightness and no friction between the valve seal and the seat, which significantly reduces their wear.

The disadvantages of this type of valves are strong hydraulic resistance and, accordingly, large energy losses, limitation of the maximum diameter of pipelines on which they can be installed, as well as the existence of stagnant zones (due to the S-shaped internal cross-section) where impurities can accumulate and garbage.

Operating principle of a gate valve

In the "open" position

Step 1

Step 2

In the "closed" position

The design of a gate valve resembles a sluice - the flow is regulated by dividing it using a metal plate - a gate. A gate valve is one of the simplest devices for regulating flow.

Gate valves, depending on the design of the locking element, can be wafer-type, double-sided or knife-type.

The advantages of a gate valve include the fact that this type of valve, when open, does not contain any elements that impede the flow.

Operating principle of a diaphragm valve

In the "open" position

Step 1

Step 2

In the "closed" position

Diaphragm valves use a flexible membrane (diaphragm) as the shut-off element, a "pinch" method to stop the flow of the valve using the flexible membrane. 

One of the advantages of a diaphragm valve is that the components of the valve itself are separated from the medium flow, which in the case of aggressive media increases the service life of the valve, subject to regular maintenance and timely replacement of the membrane.

These types of valves are generally not suitable for aggressive environments and environments with high temperatures; they are mainly used for plumbing systems.

Below is a video that clearly shows the principle of operation of a three-eccentric butterfly valve

Source: https://rgk-palur.ru/zaporno-reguliruyushhaya-armatura-princip-dejstviya/

Shut-off and control valves for heating: features, types, parameters and characteristics:

Every residential building requires shut-off and control valves. It is responsible for certain functions in the heating process. The main function of shut-off valves is to shut off the flow of liquid. A regulator is needed to adjust the water flow. For installation, you need to choose the right design. In today's article we will talk in detail about this fittings.

What parameters should be taken into account when choosing?

When choosing shut-off and control valves, you should pay attention to the type of device. It is important to know what size of fittings is needed for a particular living space. It is worth considering all additional nuances. The shut-off and control device of the fittings must be responsible for increasing and decreasing the flow of liquid circulation in heating radiators. It is worth paying attention to the diagram of radiators in the house before installation.

What types of shut-off valves are there?

These fittings are special devices. They help shut off the flow of fluid in the system.

Types of shut-off and control valves:

1. Ball Valves. They are the most popular among devices of this type. A special ball is fixed inside the device, which has a through hole. When a person turns the handle, the ball begins to rotate. Cranes of the required type are characterized by low cost and high demand in the market. It is worth remembering that this device cannot be repaired if it fails. It is only possible to install a new faucet.
2. Rod or valve valves. When the rotation knob is turned, the fluid flow is blocked. Due to the handle, the valve goes into a specially equipped seat. These devices are more expensive than ball valves, but have a longer service life without breakdowns. Another great feature of these faucets is that they can be repaired if they malfunction. The valve valve is easy to repair with your own hands. This element can also regulate the pressure of water flow in the system, decrease and increase. The composition contains a rubber gasket. To turn off the heating, you need to turn the knob several times. The rod valve allows you to smoothly control the water pressure in the system.

Some install valves that act as rod valves. They are suitable for small diameter pipes.

Why install a separate tap for each battery?

Many citizens wonder why install shut-off, control and safety valves on every radiator in the house. It is believed that by installing separate elements on each battery, it is possible to reduce repair work in the event of equipment leakage. To cope with the problem, it is enough to turn off one battery and calmly carry out repairs. There is no need to shut down the entire system, which will prevent inconvenience for all residents during the repair.

What does the fittings include?

The composition of the control valves includes:

1. Mayevsky valve, which is needed to remove excess air from the operating system. A needle tap is installed in the side of the fittings. It is needed for heating system radiators.
2. Check valve. It is necessary to ensure that the water in the system cannot move in the opposite direction. This type of valve is ideal for installation in a private house or cottage where there is a heating boiler. Check valves are needed for houses with complex heating system wiring.
3. A safety valve is a type of fitting that performs a protective function. It prevents deformation of the heating system when excess pressure is generated. The valve in question has an additional pressure gauge. The safety valve is used to prevent sudden pressure surges and pipe rupture.
4. There are also mixing units. They are often used to equip heated floors in apartments.
5. Thermal heads are needed to select the desired temperature in the room. You can choose a mode with a comfortable temperature in the room. Typically, thermal heads are used when there is a heating boiler in the house. The valve is installed directly on the battery. Mechanical or manual options are available.

You should know that any type of control valve can have a manual as well as an automatic control system. Sometimes shut-off valves are installed as control valves. But this is rare.

How to choose the right size?

Before purchasing, it is important to accurately select the correct size of the device. It is worth determining what diameter is required. It must exactly match the diameter of the pipe in the heating system. The shut-off and control valves of the pipelines must correspond to the room in which it will be installed.

Why is it important to know what the device is made of?

It is also worth considering what material the faucet is made of and what company produces it. Fittings for the heating system are made from different materials. It can be made of brass, bronze. There are options when the device contains stainless steel or plastic.

It is believed that the strongest devices are made of bronze and brass. The choice of the required materials is based on the fact that they cannot be damaged by corrosion or mechanical means.

If the fittings are made of steel or silumin, then the service life will not be long. These materials are soft and easily deformed during the use of reinforcement.

If the pipeline is made of plastic, then it will require plastic taps. This type of valve should not be installed on pipelines made of other materials.

Which valve manufacturers have proven themselves in the market?

Nowadays, many manufacturers are engaged in the production of shut-off and control valves. The most popular manufacturers are Valtek, Danfos and Bugatti. These companies are recognized by their high-quality products, which do not fail during operation and serve without complaints for a long time.

Installation methods

There are several installation methods:

1. When fittings are installed using threads. This type includes ball valves.
2. When a device is secured using flanges, it is called flanged. Suitable for pipelines installed outdoors.
3. Threaded fittings are suitable for residential buildings. It is small in size.

What is required for installation?

To install shut-off and control valves for heating, you will need:

1. Adjustable wrench of the required diameter. It is possible to replace it with a wrench of the same diameter.
2. Materials for insulation: FUM tape, special threads.
3. Thread cutting machine.
4. Bulgarian.
5. Marker for marking, tape measure.

How is coupling fittings installed?

A part of the pipeline is cut out; installation work with fittings will be carried out in this place. After this, the end of each pipe is stripped. The next step is cutting the threads. This process is quite labor-intensive. Upon completion, the threads on the reinforcement are sealed with a special sealing material, which is purchased in advance at a hardware store. As a result, the valve is installed on the pipeline.

It is worth taking care in advance to turn off the water in the heating system before starting work.

Installation of flange fittings

To correctly install flange fittings, you need:

1. Precisely cut and prepare pipes for installation.
2. Correctly secure the flanges to the pipes. Welding is often used for better fixation.
3. After installing the valve, it must be tightened with the fixing bolts to the flanges.

Conclusion

So, we looked at what shut-off valves are and what types they come in. As you can see, even a beginner can handle installing the fittings. It is important to follow the instructions and not change the order of the installation steps. Shut-off and control valves make the operation of the residential heating system more comfortable for people.

Source: https://www.syl.ru/article/429188/zaporno-reguliruyuschaya-armatura-dlya-otopleniya-osobennosti-vidyi-parametryi-i-harakteristiki

Detailed characteristics of shut-off and control valves

To tightly shut off the flow of water, in addition to shut-off valves, shut-off and control valves can be used. It is an inseparable part of heating and water supply systems.

Shut-off and control valves

Shut-off and control pipeline valves combine the basic characteristics of control and shut-off valves and are used to control flow, compliance with specified parameters, and correct mixing of liquids and gases.

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Main types of shut-off and control valves

Shut-off and control valves are used for heating and water supply systems, steam systems, as well as in industry for petrochemical, chemical and pharmaceutical enterprises, where they perform the task of regulating the flow of liquid, steam or gas. The following types of devices are distinguished:

1. Saddle.
2. Ball.
3. Wedges.
4. Slide-knife.
5. Rotary disc.

Shut-off valve device

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General characteristics of globe valves

Saddle fittings can be used for heating and water supply systems both for the purpose of regulation and limitation, and as a shut-off valve. The main types of saddle fittings include the following components:

• Packed shut-off valves;
• Angular;
• Bellows;
• Regulatory;
• High pressure valves;
• Boiler blowdowns.

The design of the saddle valve body is made in various versions depending on the type of connection, which is necessary for engineering systems. Valves are available with the following connection options:

• Coupling;
• Flanged;
• Threaded;
• Welding.

Bellows fittings

There are different types of saddle fittings depending on the material of manufacture. The main varieties include a body of:

• Gray and ductile iron;
• Cast steel;
• Of stainless steel;
• Bronze.

A wide range of operating temperatures (-60 - +450 ˚С) allows the use of seat valves for heating and hot water supply systems.

Durable and chemically resistant materials that are used to manufacture the shut-off valve allow the use of such components in both neutral and aggressive liquids and gases. This is the most profitable option for shut-off and control valves in terms of cost and technical capabilities.

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Characteristics and features of the use of ball valves

In ball devices, the movable part of the shutter plays the role of a regulatory element. Such devices are used for plumbing systems and include the following types:

• High pressure ball valves;
• Three-way regulating;
• Industrial;
• Ball valves equipped with metal seats.

Ball Valves

The main advantages of ball valves, which distinguish them favorably from other types of shut-off and control valves:

• Minimum hydraulic resistance;
• Device reliability;
• Ease of operation;
• Performance;
• Suitable for fire and explosive, toxic and aggressive environments.

Ball valves can have various designs of end elements and connections, namely:

• Threaded;
• Flanged;
• Welded.

Ball valve device

Ball valves can be equipped with electric or pneumatic actuators to automate the process of adjusting the water flow. The convenience of ball valves is their long service life and minimal maintenance.

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Wedge valves as flow regulators

Wedge valves are characterized by perpendicular movement of the control element in relation to the flow of liquid or gas. Wedge valves can be used for water supply, heating, gas supply systems, as well as oil pipelines, technological and transport pipelines. Key features of the device include:

• Possibility of operation in any conditions;
• Simplicity of design;
• Reliability;
• Wear resistance;
• Low hydraulic resistance;
• Service life is up to 30 years.

Wedge valves

The disadvantages of wedge valves for heating include:

• Long valve closing time;
• Difficulty in carrying out repair work.

Although there are options for gate valves, these are still rare. Most often, wedge valves are used as exclusively shut-off valves, which operate in two positions - open and closed.

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Knife gate shut-off and control valves

Gate valves are equipped with a flat-shaped locking element - a gate. Depending on the type of construction, there are:

• Single disc valves;
• Double disc.

This type of shut-off and control valves is used for work in difficult working environments - for wastewater processing, water purification, processing of mineral raw materials, chemical products. The main advantages of gate valves:

• Minimum maintenance requirements;
• Full bore;
• Easily replaceable ring elements;
• Complete isolation of the gate knife from the solution flow in the open position.

Knife gate valves

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Characteristics of butterfly valve

A rotary disk is used as a locking and regulating element. Dampers are widely used in heating, water supply and air conditioning systems. The operating medium of the damper can be process or treated water. The main elements of this device are:

• Frame;
• Disk;
• Upper shaft;
• Lower shaft;
• Saddle;
• Bearings;
• Lid;
• O-ring;
• Thrust ring;
• Pinch bolt;
• Key;
• Liner;
• Nuts and washers.

Butterfly valve

The main advantages of this device are:

• Low cost;
• Easy to operate and maintain.

Disadvantages of the butterfly valve:

• Sensitivity to pressure changes;
• Limited ability to regulate the flow of working fluid.

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Technological process of operation of shut-off and control valves

Interesting on the topic:

Source: http://VseOTrubax.com/armatura-i-fitingi/armatura-i-ventili/detalnaya-xarakteristika-zaporno-reguliruyushhej-armatury.html

Shut-off control valves: basic information and areas of application

The valves, which are designed to set and maintain parameters in pipelines for various purposes, are called shut-off and control valves. It includes control valves, valves, gate valves and much more.

The task of shut-off and control valves is to maintain the specified parameters of the liquid or gas (pressure, temperature, etc.) circulating in the pipeline system. Various materials are used for the production of fittings - polymers, cast iron, steel alloys, etc.

Problems solved using fittings

The concept of setting and maintaining characteristics includes the following:

• adjusting the flow rate of the working medium;
• maintaining operating pressure within specified limits;
• mixing various liquids and gases in the required proportions;
• maintaining the required level of the working environment in tanks and vessels included in the pipeline system.

The solution to all the described problems occurs by changing the flow parameters of liquid or gas as they pass through the working section of the valve. Various methods are used to control the operation of devices of this type. As a rule, third-party energy sources are used to solve this problem. The valves are controlled by command from the control center, which receives data from sensors that are part of the devices installed on pipelines.

The type of valve control is determined by the conditions in which the shut-off and control devices are operated. It should be noted that in recent years, manual control of valves has become less and less common.

The characteristics of the medium, namely pressure, temperature, its chemical composition, place different demands on the fittings. This, in turn, has led to the fact that many models of equipment of this type have been developed and are used in practice.

Each device can be considered as a component of an automatic control system for technological processes that take place in a variety of environments. The operation of such equipment is adjusted under the control of commands coming from a single control center for the operation of the pipeline system.

Main types of devices

Devices of this type are similar in appearance to shut-off valves, but at the same time have their own specifics. These valves can be divided according to the type of flow, or more precisely, its direction:

1. Continuous - a valve of this class is installed on straight sections of pipeline systems in which there is no change in the direction of movement of the working medium.
2. Angular - they are installed in places where the direction of flow changes by 90 degrees.
3. Three-way. They include three pipes for connection to the pipeline system. In the body of this device, two flows of the working medium are mixed into one. This device is often called a mixer.

Control valves also differ in the design of the regulators. This classification looks like this:

• single saddle;
• two-saddle and many others.

The operation of control valves can be controlled using electric, pneumatic and electromagnetic actuators.

Shut-off valve

This device is used to adjust the parameters of the working environment in accordance with the required characteristics. The required result is achieved by changing the working section in the valve body.

Changing the section size is carried out using a locking device. At its core, a shut-off valve is a single-seat valve.

Mixing tap

This device is used when there is a need to mix two or more types of liquids supplied through a pipeline system, for example, cold and hot water. In this case, one of the parameters, for example, temperature, can be constant.

Mixers differ from control valves in that they determine the flow rates and parameters of two working media simultaneously.

Direct acting pressure regulators

Devices of this type are designed to maintain operating pressure in a pipeline system at a constant level. This need arises if, during operation, sudden pressure changes occur that are unacceptable for stable operation of the system.

The difference between this device and another type of valve (indirect action): the parameters are adjusted directly from the working environment without the use of third-party energy sources. In addition to regulators of this type, direct-acting valves also include equipment such as safety and check valves. These devices are classified as protective pipeline fittings.

Most often, direct-acting regulators are used, which are equipped with a diaphragm drive..

Source: https://tokar.guru/metallicheskie-izdeliya/armatura/zaporno-reguliruyuschaya-armatura-primenenie-na-praktike.html

Shut-off and control valves: types, which is best for water and heating pipelines, application and do-it-yourself installation

Hello dear reader. We live in an age of increasingly complex technology. The modern pipeline system both at home and at work is essentially an analogue of the circulatory system - without it, modern life is impossible.

Our requirements for comfort at home and increased productivity in the workplace include the need for quick, easy and, if possible, automatic control of the operation of piping systems.

And here shut-off and control valves come to our aid - we will talk about them in this article.

What it is

This is a type of pipeline fittings that combines the functions of control and shut-off mechanisms and regulates the parameters of the working environment:

• consumption;
• pressure;
• temperature;
• liquid level;
• mixing media in given proportions and some others.

The main control method is to change the flow rate of the medium by changing the cross-section of the passage of the fittings (up to complete shutdown of the pipeline)

Application area

Control valves are widely used in all spheres of human activity: in industry, in the mining complex, construction, agriculture, residential complexes, and urban infrastructure. By area of ​​application it is:

• general purpose - serial devices for all areas of human activity (from engineering equipment for housing to industrial enterprises); work in non-aggressive environments with low pressure and temperature;
• for special operating conditions - for work in conditions of high or low temperature, high pressure, aggressive environments;
• You can also highlight special fittings - products made to special order, often in a single copy, for exclusive equipment or testing new experimental equipment.

Operating principle

The operating principle of all types of pipeline fittings is based on limiting the flow of the medium (liquids, gases, bulk materials) up to its complete blocking.

Classification and types

Classification by control method:

• with manual control;
• drive – large equipment is controlled using a pneumatic or electric drive;
• with remote control - controlled using transition devices (all kinds of rods, speakers, etc.);
• with automatic control - adjustment occurs without operator participation: either directly when the pressure of the working medium is applied to the valve, or when the drive is turned on by a signal coming from the control and measuring equipment.

Classification by functional purpose:

• shut-off and regulating;
• regulating;
• distribution and mixing (three-way or multi-pass);
• mixing and adjustment;
• safety;
• protective;
• control room (used to determine the liquid level in boilers, tanks, connect pressure gauges, thermometers, level indicators);
• reduction or throttling (reducing pressure in the system);
• phase separation (condensate traps, air vents and oil separators).

By installation method: on threaded connections (coupling, pin-type), on flanges. Control valves are not installed during welding.

Types of shut-off valves by design:

• control valves (gates); including shut-off and control and mixing valves;
• taps;
• valves;
• flaps.

Design of shut-off control valves

The design of the control equipment is similar to that of the shut-off device.

The most common type is a control valve, which changes the flow of working fluid. In the direction of flow of the working medium, there are passages (for straight sections of pipelines); angular – rotate the flow of the medium by 90°; mixing (three-way) - mix two flows into one. Structurally, the valves consist of a body with a seat inside, a spindle with a handle, and a locking element; There are single- and double-seat, cage, membrane, spool valves.

Shut-off and control valve is a single-seat valve that can completely shut off the flow of the working medium or regulate its flow.

Mixing valves are used to mix several media in certain proportions, yielding a medium with certain parameters (composition, temperature) at the outlet. For example, the well-known household mixer belongs to this type.

Gate valves consist of a body, a spindle, and a locking plate that moves perpendicular to the flow of the medium.

The dampers have a rotary-disk locking system: the disk rotates around an axis perpendicular to the flow of the medium.

In faucets, the shut-off element rotates around an axis using a handle in the body.

Advantages and disadvantages

• The valves have high tightness with small sizes and can be used at high temperatures and pressures, but have high hydraulic resistance and are used for small diameters.
• The valves have a simple design and small dimensions, quickly open/close the passage, but do not operate at high pressures (and ball valves at high temperatures) and are not tight enough for use in gas systems.
• The valves are highly reliable over a wide range of temperatures and pressures, but have a long response time. Knife gate valves have a locking body in the form of a plate capable of cutting dense inclusions, which makes them suitable for use in thick and dusty environments (powders, pulp, dusty gases).
• The valves have a simple design, high reliability, can be used in large-diameter pipelines, but have high hydraulic resistance and are difficult to control.

Life time

The service life of the fittings depends on the material and operating conditions (temperature, pressure, aggressiveness of the environment). There is not enough space on the site to describe all the features of operating industrial equipment, so a few words about household appliances.

Modern thermal valves are designed for a service life of more than 10 years. There is no fundamental difference between mechanical and electronic ones in terms of service life - the main thing is to initially choose a quality product.

Tips for choosing

In practice, there are two types of control valves in everyday life: mixers and temperature controllers for radiators (thermal valve). When choosing a mixer, you should choose a lever design - it will last longer.

The optimal material is bronze (look inside - the characteristic golden-yellowish color cannot be confused with anything else).

The quality of elite expensive models guarantees their durability, but the price outweighs their durability - and on the domestic market you can choose a quality product.

When choosing a thermal valve, you should be guided by the purchase in a construction supermarket and the availability of a warranty, as well as a well-known manufacturer.

You should not be guided only by considerations of economy - the thermostat will reduce heating costs in the future and its cost will be fully recouped.

DIY installation of shut-off and control valves

Here we will talk about how to install automatic regulators with your own hands when installing radiators. This work requires some skills, but is quite accessible to a novice home craftsman.

Required tools and equipment

No special tools are required to install thermal heads. You will need: a pair of adjustable wrenches, FUM tape (gaskets are included with the thermostat), and the thermostat itself.

To solder MRN you will need: scissors for cutting plastic pipes, a device for soldering plastic pipes and fittings - MRN, 90° angle

Installation procedure

Installation procedure:

• Drain the water from the radiator and disconnect it from the system. If you have a single-pipe heating system and radiator connections and the work is carried out during the heating season, then you should install a bypass;
• the thermostat is screwed into the plug through which coolant is supplied to the radiator and replaces the tap for connecting the battery;
• the arrow on the regulator body must coincide with the direction of water flow in the heating system;
• the radiator is installed in place - instead of a tap to connect the battery, it is necessary to solder the MRN and an angle (bend) to the heating system;
• the radiator is filled with water, checked for leaks, air is bleed through the Mayevsky tap;
• The thermostat is being adjusted.

for installation

All the details of the thermostat installation process can be seen in the video.

Expert advice

The thermal valve should not be covered by curtains, furniture, or decorative covers. In this case, it is necessary to connect a remote sensor to the thermostat, located a few meters from the radiator. The thermostat should not be exposed to direct sunlight or heat from heating devices, or cold from the front or balcony door. The installation height of the thermal head from the floor should be at least 800 mm.

When purchasing, you need to select a thermostat that, in terms of its technical characteristics and connection diagram, is suitable for the size and type of batteries (primarily material: cast iron, aluminum, steel), pressure (in private houses, the pressure in the system is less than in high-rise buildings).

Areas and features of application of shut-off control valves

To perform maintenance on a separate section of the pipeline, it is necessary to use shut-off and control valves. With its help, you can shut off and regulate the supply of liquid or gas during system repairs.

Shut-off control valves for water supply

Characteristics and purpose

Shut-off and control valves are used in the manufacture of pipelines for water, gas and other liquids. These can be water supply, heating, gas supply, sewerage systems.

The parts are used to regulate pressure, flow rate, and temperature of the medium without completely shutting off the entire line. Shut-off elements are installed at branching points to make it possible to close individual circuits at the right time. These parts have a number of technical characteristics that determine their capabilities:

• control - manual, automatic;
• throughput;
• possible adjustment of the regulator;
• regulation zone;
• travel range of the locking mechanism;
• relative leakage.

The higher the capacity, the stronger the flow will pass through the control mechanism. This indicator must correspond to the maximum permissible pressure that the pipes can withstand so as not to compromise the integrity of the pipeline.

Technical requirements

Control valves must meet a number of requirements:

1. Strength indicator. It determines the durability of the product. The part must not have visible damage, irregularities, or cracks. Connections must be tight.
2. Resistant to high temperatures and acids. This requirement applies to different types of pipelines. If a chemical substance flows through the line, chemical-resistant parts are used in its manufacture.
3. Accuracy of shut-off valve position control. The exact values ​​are indicated on the packaging. Deviations from the manufacturer's specifications are considered defective.
4. Lifetime. Products have a period during which they will work without breakdowns. For this period, the manufacturer issues a warranty card.
5. Internal and external tightness.

Products need to be periodically changed and repaired. Because of this, installation should be convenient and not cause serious difficulties.

Principle of operation

Control valves operate on the same principle, regardless of their design. After turning the control knob or screw, the working part of the product begins to move, blocking or blocking the pipeline.

Classification

Parts for the manufacture of pipelines are usually divided according to various factors. Any types of shut-off and control valves are sold in a construction or plumbing store.

A separate division concerns the design of shut-off valves:

1. Ball devices. There is a ball inside the housing that blocks the flow of liquid.
2. Rotary disc mechanisms. They have a disk-shaped valve, the position of which is regulated by a valve.
3. Seat valves. The current is blocked using a plunger.

You need to choose a design depending on the required technical characteristics and capabilities.

Ball inside the body

By application

Types of fittings by purpose:

1. Locking products. Designed only to block the flow of water, gas or air.
2. Regulating parts. With their help, you can regulate the flow of the working flow, but you cannot completely block the highway.
3. Shut-off and control products. In extreme positions, the handle completely opens or closes the damper. Intermediate positions are designed to regulate the work flow.

By connection method

There are several types of fittings based on the connection method:

1. Coupling - suitable for pipelines operating at low and medium pressure. They have threads on the inside.
2. Tail type - designed for small diameter tubes that operate under high pressure.
3. Fitting - parts that have threads on both sides.
4. Welded fittings are a durable type of connection used for systems operating under high pressure. The main disadvantage is the inability to make out the shock.
5. Flanged - connected using bolts and nuts. For tightness, special rubber gaskets are used.

Each type of connection has its own characteristics, a certain indicator of tightness and strength.

Replacement and installation

There are a number of rules that must be followed during installation:

1. Clean the joints from dirt, dust, and deposits.
2. To prevent large-diameter locking parts from sagging over time, additional support must be provided for them.
3. Do not apply too much force when tightening.
4. Water hammer may occur on individual circuits, which can break connections. For stability, in addition to them, it is necessary to install a check valve that will relieve pressure.
5. Install parts only on flat sections of pipeline. Excessive tension is generated at the bends, which can break the product.
6. During installation, open the valve completely.

The flanges must be straight.
Any unevenness will lead to loss of tightness. Electronic catalog of Gusar plant products
Shut-off and control valves are used to adjust and completely shut off pipelines. With their help, you can turn off the system for repairs or replacement of individual elements.

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Source: https://trubyda.ru/armatura/zaporno-reguliruyushhaya

Shut-off and control valves (general information and types) | Pipe fittings | Articles

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Flow control in pipeline systems, lines and sections is carried out using devices collectively called pipeline fittings. Fittings also include connecting elements of pipelines - flanges, tees, couplings, etc.

Shut-off and control (pipeline) valves are devices designed to shut off or distribute the flow of a medium, regulate various parameters of technological processes (pressure, head, temperature, amount of supplied substance, etc.). Regulation of technological processes is carried out by changing the flow rate of the transported medium.

Pipeline fittings are mounted on pipelines, tanks and other units in which it is necessary to disconnect, distribute or regulate the flow of transported or used media.

According to their functional purpose, pipeline fittings are divided into types, the main ones being (according to GOST R 52720-2007 Industrial pipeline fittings):

• shut-off valves,
• control valves,
• shut-off and control valves,
• protective fittings,
• safety fittings,
• mixing fittings,
• phase separating fittings.

Shut-off valves

As the name suggests, shut-off valves are designed to completely shut off the flow of medium in a pipeline. This is the most common type of pipeline fittings. More than 80% of all valves are shut-off valves.

Control and shut-off and control valves

Control valves are designed to maintain the required values ​​of certain parameters of technological processes by regulating the flow of the working medium. The main controlled parameters are temperature, pressure, composition and concentration of substances involved in the process. In design, it is similar to a shut-off valve, and often the same types and even brands of pipeline fittings can and are used both as control and shut-off valves.

Control valves also include throttling valves, which are designed to significantly reduce the pressure of the medium and operate under conditions of large pressure drops.

Safety and protective fittings

Safety and protective fittings are designed to eliminate the negative impact on the equipment of the working environment in case of exceeding the permissible values ​​of pressure or direction of flow of the working environment.

The difference between safety valves and protective valves is that when an emergency condition of an environmental parameter occurs, the safety valve opens to release an excess amount of the working environment, and the protective valve closes, cutting off the protected section from the rest of the pipeline, which protects it from unacceptable influences.

Mixing fittings

Distribution and mixing fittings, designed to distribute the flow of the working medium in certain directions or to mix the flow of the medium, are used mainly in heating systems to achieve the required coolant temperature by mixing incoming and return water.

Phase separating fittings

Phase separating fittings are designed for automatic separation of working media depending on the phases and state of these media.

The connection of the fittings to the pipeline can be carried out using couplings with internal threads, pins on external threads with a seal, nipples, using flanges or welding.

Welding is one of the most reliable methods of connecting elements of a pipeline system; in addition, when using high-pressure fittings, a welded connection becomes the only possible one.

Flanges are a flat ring or disk with holes for bolts and studs; they are made mainly from carbon, alloy and stainless steels and other metals. Flanges as separate parts are most often welded or screwed to the ends of the parts being joined, although often the flange may be part of the part or pipe itself.

Tests for the tightness of pipeline fittings, for the strength of the body, components, parts - checking the compliance of the object with the established technical requirements must be carried out before installation on the pipeline. Ideally, this should be done by a product supplier who provides a guarantee of the quality of their products.

Source: http://www.podvod.ru/stati/truboprovodnaya-armatura/zaporno-reguliruyushaya-armatura-obshie-svedeniya-i-vidi

Purpose of control valves

Any pipeline includes in its design devices designed to regulate, turn off and on, and move substances, which are called “fittings”. They all have their own classification, including control valves. This type allows you to maintain pressure, level and flow within the required limits. Let's take a closer look at the main types of control valves and their purpose.

Types of control valves

Due to their design features, control valves are very similar to shut-off valves. Therefore, these elements often have the same brand. Regulating devices are divided into 2 types:

• pressure reducing, which works to reduce the pressure of the working environment;
• shut-off and regulating.

Now about the types of control valves. The most common type is considered to be control valves, which are also divided into several subtypes:

• checkpoints;
• corner;
• mixing systems with a three-way design.

Other types of control devices include shut-off and control valves, direct-acting pressure regulators, and level regulators.

All of the listed devices will be discussed in more detail below.

Features of control valves

Control valves, as mentioned earlier, are among the most common types of shut-off devices. Their main function is to change the pressure of the medium that passes through a certain pipeline system. Scope of application of these devices:

• plumbing systems;
• gas supply systems;
• pipelines designed to transport petroleum products and gaseous substances.

The material used for the manufacture of this fittings can be varied: brass, cast iron, steel, high-alloy alloys. The choice of a specific design depends on the piping system and its environment.

Depending on the operating features, all control valves are divided into 2 types:

• with a manual drive, where control occurs using a specially built-in steering wheel, which, if necessary, must be rotated by hand. For pipes with large parameters, this option is practically not used, since bringing the control device into operation requires considerable effort;
• with automatic control, where work is performed due to the built-in hydraulic, pneumatic or electric drive. To ensure timely operation of the valve, the control device includes sensors that measure the existing pressure in the system.

There is also a classification of control valves depending on their shape:

• pass-throughs are installed on a straight pipeline and do not affect the direction of the medium in any way;
• angular ones change the direction of the medium, and therefore the pipeline itself, by 90˚;
• Mixing systems include 3 pipes in their design, which allow two working media to flow together.

Operating principle of shut-off and control valves

The main purpose of shut-off and control valves is to control the working medium in the pipeline and change its flow. This control valve can be used in the following systems:

• heating and hot water supply networks;
• central and individual heating points;
• ventilation system.

For each condition there is a certain type of execution and material used.

Shut-off and control valves are universal control devices. This is explained by the fact that they not only control the flow of the medium used in the pipeline, but also perform a shut-off function that can completely block the flow.

Let's consider the principle of operation of shut-off and control valves: inside the housing, the shut-off element moves due to the rotation of the rod, which is driven manually or using the provided drive. A special feature of this control device is the presence of a seal, thanks to which when the rod is lowered, the system is completely sealed.

Shut-off and control valves have a number of advantages, the most important of which are ease of use and maintenance, and reliability in operation. Installation of control devices is possible not only on standard-type pipelines, but also on pipelines with non-standard angles and turns. In addition, they are often used to work in aggressive environments.

Level Control Information

The purpose of the level regulator is to maintain the level of the working medium (liquid) within the required limits and at a given height. The vessel used may be under pressure, or it may be connected directly to the atmosphere, which is much more common.

Such conditions are typical for tanks filled with oil products or water. The pressure indicator here is maintained at a given level by introducing an additional volume of liquid. In this case, the control valve is called a power regulator.

When liquid is released from a reservoir under excess pressure, the control valve is called an overflow regulator.

The active and main elements in such control valves are a level position sensor, more often called a sensitive element, and an actuating element, presented in the form of a control or shut-off valve.

The operating principle of such a device is based on stopping or regulating the supply of the working medium (liquid) using an actuator, the operation of which depends on the command notification of the built-in sensor.

For direct-acting level controls, the sensor is usually in the form of a hollow spherical float connected to the valve gate. When the water level increases or decreases beyond the established limits, the float creates a lifting force, which moves the valve lever in the direction specified for the operation of the regulator actuator.

The use of various types of shut-off and control valves in pipeline systems

Any system periodically requires shutting down some areas, for example, for inspection or maintenance. To do this, shut-off and control valves are installed in the pipelines, with the help of which it is possible not only to block the movement of the working medium in the pipes, but also to regulate the optimal values ​​of the operating parameters to maintain its high-quality operation.

Requirements for shut-off valves

Shut-off and control devices, regardless of whether they are installed at the end consumer or on large highways, are subject to a number of general requirements. They are taken into account during design.

Each of these requirements is guaranteed, that is, it has certain deadlines and deviation parameters. The manufacturer guarantees that if installed correctly, the requirements will be met and deviations in operating parameters will not exceed the specified values.

Requirements for shut-off and control devices:

• Regulation accuracy. The part must operate exactly within the specified values. For example, per unit of time, pass only the volume of liquid that is specified or maintain a specified pressure inside the system. Deviation of these parameters from the specified ones indicates a malfunction of the fittings.
• Strength. The device must not be deformed before it is installed in the system and must be resistant to mechanical loads. Strength determines the longevity of the part.
• Temperature and chemical resistance. These requirements are not necessary for all types of products. In the heating system, it is important to install parts that can function at high temperatures, and for cold water supply, this parameter can be omitted. Chemical resistance is important where the internal environment is chemically active, i.e. it entirely depends on the properties of the materials from which the device is made.
• Tightness. There are two types of tightness: relative to the external and relative to the internal environment. All devices must be completely sealed with respect to the external environment. This means that there should be no leaks of liquid or gas into the external environment at the places where they are installed. Tightness relative to the internal environment reflects the possibility of redistribution of liquid or gas on both sides of the valve outside the specified parameters, for example, if a certain amount of liquid passes through the shut-off valve into that section of the pipeline that is disconnected from the system.
• Durability. Each type of fittings, depending on the design features, the material from which it is made and operating parameters, has its own warranty period. Since replacing shut-off valves and valves is somewhat difficult, preference should be given to the most wear-resistant parts.

Note! Most types of shut-off and control valves, when used correctly, can last at least 30 years, although manufacturers provide a guarantee for a shorter service life.

• Easy to use. All areas of the system must be periodically checked, repaired, and cleaned. The part should be simple enough to reduce maintenance effort.

Types of shut-off and control valves

Locking and regulating parts differ in purpose and method of operation.

There are three types according to their purpose:

1. Exclusively shut-off valves are used to block the flow of liquid or gas. The valve has two positions: it allows the flow of the internal medium to pass through and does not allow the flow of the internal medium to pass through.
2. Exclusively regulatory. They cannot completely block the flow, only regulate its parameters.
3. Locking and regulating parts. The extreme positions of the valves correspond to shut-off positions, that is, they either allow or do not allow liquid or gas to pass through. The intermediate positions correspond to the regulatory ones - they allow the internal environment to pass through in accordance with the specified parameters.

Shut-off and control valves, in turn, are divided into several types:

• Seat valve. It is most often used on large main pipelines. The plunger serves as a moving part inside such a valve. This is a piston that is able to move, thus regulating the flow parameters.
• Ball devices. Inside such parts there is a ball with a through hole. It is capable of turning 900 around its axis. When the hole is parallel to the flow, the medium passes through the device; when it is perpendicular, it does not; intermediate values ​​determine partial throughput.
• Wedge fittings. Inside this part there is a wedge that moves perpendicular to the flow of liquid or gas. The principle of its operation is similar to the principle of a damper, which moves from top to bottom. At the highest possible position, the entire flow passes through the fittings; when completely lowered, nothing passes through. Intermediate positions allow some liquid or gas to pass through.
• Rotary disc devices. They are a valve that looks like a disk to which a control valve is attached. The diameter of the disk corresponds to the cross-section of the reinforcement. If the disk is located perpendicular to the flow, the liquid does not pass through, if it is parallel, all of it passes through. Intermediate positions are adjustable.

Shut-off and control devices for heating systems

Heating systems differ from other systems, which use devices that can operate at high temperatures. The material from which the parts are made must have significant heat resistance, for example, stainless steel or bronze.

In different areas of the heating system, shut-off and control devices, only shut-off or only control devices are installed.

Each of them has its own purpose:

• Taps are needed where the pipe has branches. Using a tap, you can completely or partially redirect the coolant flow to another direction or shut off the main line.
• The Mayevsky crane is an improved ball device. It is needed to bleed air from the system. When closed, it creates a completely sealed barrier, and when open, it allows only air to pass through.
• Check valves are installed on pipes where unwanted backflow of coolant is possible. They allow liquid to flow only in one direction along the flow and prevent it from returning back.
• Mixing units allow you to mix cold and hot water. The temperature in the distal section of the pipe depends on the position of the valve.

Source: https://InfoTruby.ru/armatura/zaporno-reguliruyushhaya

Shut-off and control valves for heating systems

The normal functioning of any water heating system is impossible without shut-off and control valves. These elements are present in all areas of the circuit, from the boiler installation piping to the very last radiator. This material is devoted to the question of what shut-off valves are used for heating and what functions they perform in a given case.

Shut-off and control elements of systems

These include the following devices:

• balancing valves;
• automatic differential pressure regulators;
• thermostatic radiator valves.

Balancing valve

The listed types of shut-off and control valves are designed to carry out quantitative regulation of the coolant. That is, by partially blocking the flow section of the pipeline, these elements provide a certain flow of water entering a section of the system or into a heating device. Balancing valves are installed both at the outlet of the batteries and at the beginning of a branch or riser of the system, as a rule, on the return line.

Valve diagram

With a large number of batteries, the disposition may change and the installation of shut-off and control valves is carried out using automatic differential pressure regulators. They are placed together with valves and connected to them by a capillary tube. The balance valve provides the required coolant flow to the branch or riser, and the regulator adjusts it in accordance with the operation of the radiator thermostats.

Application of automatic valve

Automatic thermostatic valves are fittings for radiators that reduce or increase the flow of hot water through the radiator depending on the room temperature.

Valves with thermal heads

It is installed on the supply line and can be additionally equipped with a thermal head and a remote thermostat for more precise control of coolant flow. It is considered an integral element of modern schemes and one of the main means of saving energy.

Thermostatic valve

Mixing and control valves

A prominent representative of this group of devices is the thermostatic three-way valve. Its task is high-quality regulation of the coolant, that is, by temperature, and not by flow. A three-way valve does not act like a shut-off valve, it works like a mixing unit. Configured to produce coolant at a certain temperature, the element mixes the two flows in the required proportions.

Heating mixing unit

The device is a brass body with three pipes, inside of which there is a rod controlled by a thermostatic drive. The rod passes through 2 seats, regulating the flow of the required amount of water through them from two pipes, in order to obtain a mixture of the set temperature in the third.

Operating principle of three-way valve

It must be said that not every heating system needs such fittings. The scope of application of mixing devices is maintaining the temperature in underfloor heating circuits, individual radiators or entire groups of heating devices, as well as in small circulation circuits of solid fuel boilers. In general, it is quite difficult to list all the special cases of using mixing valves, since there can be a lot of them in modern water heating schemes.