Shut-off valve - what is it? Device, application. Types of gate valves and principle of operation

Shut-off valves for pipelines are a means of dividing the pipeline network into separate local sections and regulating the pressure in them, depending on their purpose.

This equipment is designed to completely close / open the flow of liquids of various nature in the pipeline in accordance with the requirements technological processes. Such devices include shut-off valves, gate valves, rotary valves and taps. In turn, shut-off and control valves play the role of a flow regulator and create tightness in the pipeline medium.

Stop valves of all types are intended for use in the following environments:

• liquid and gas-liquid;
• water;
• vaporous.

For the most part, such equipment is designed to operate only in two positions: "open" or "closed" and, most often, are not used in intermediate positions.

According to their purpose, the fittings are divided into the following types:

• shut-off - to shut off the flow of the transported medium with the main condition - tightness;
• regulating - to establish a certain flow rate of the working medium by changing the nominal section of the pipeline, as a rule, it is controlled by an independent source of energy;
• distribution - division of the flow according to necessary directions, as well as for mixing different streams;
• safety - to prevent exceeding the permissible parameters of pipelines and vessels in terms of pressure by dumping the products being pumped up to stop the flow;
• phase separation - used to separate the product into various fractions and states, these include oil separators, condensate and moisture traps.

The use of shut-off valves in sewerage systems is associated with the need to turn off its individual sections for repair.

For pipelines

Product transfer, to be an effective means of transportation, is carried out over long distances at high pressure and with high speed. Therefore, special requirements are imposed on the selection of the actual pipes and valves - gate valves, valves, butterfly valves.

It is selected in accordance with technical standards, with design pressure, viscosity of the medium, differences in internal and outdoor temperature. The degree of pumping automation also matters.

In systems of main water supply systems, the pumped liquid always contains a certain amount of aggressive components. Therefore, chemically used for reinforcement resistant materials. These properties are fully possessed by cast iron, from which all types of valves for pipelines are made.

They are used in pipelines high and low pressure and for pumping various media. The same material is most popular in the manufacture of pipeline fittings for oil pipelines.

On main pipelines, shut-off valves with dimensions of 8 - 2000 millimeters are used.

Gate valves are operated manually using handwheels, and in hard-to-reach places– using an electric drive remotely.

Most cast iron gate valves are designed with flange mechanisms and can be produced in various designs:

1. Gate valves - with a movable or fixed stem;

, in which there is a flat gate with a hole corresponding to the size of the pipe. Two types of drive are used for control: manual for units located in an accessible place, and remote, if the valve is installed in a closed space.

The manual drive consists of a handle in the form of a steering wheel, a screw pair and a rod attached to the gate. When the handle is rotated, the screw pair converts the rotational movement into a translational one, which, through the rod, drives the gate in the desired direction. When the hole in it coincides with the hole in the pipe, the fluid flow resumes.

1. Wedge - a highly effective type of valves for pipelines. The shape of the locking element makes it possible to ensure the maximum tightness of the closing of the lock and the seat, which increases the quality of the overlap.

The lift of the plug moves the wedge in relation to the seat, as a result of which its hole is aligned with the hole in the stationary part, ensuring the passage of the working medium. Rotation can be done manually or using a remote control.

1. Parallel.

Such devices are designed to operate at a pressure of 2 - 200

atmospheres.

The working medium and the locking elements of the device in the form of two plates are located in the chamber. The gate plates are attached to the actuator stem. When it rotates, they open, passing water or steam through the pipeline.

All presented valves have a number of common parameters, including:

1. Connection to the product pipeline is made using flanges, couplings or welding.
2. Gate valves are not used to adjust the pressure in the pipeline, but only close or open it in extreme positions.
3. Valve bodies are made of cast iron by casting, less often - of steel.
4. In all types of these fittings, sealing devices made of rubber, paronite, cardboard, etc. are used.
5. Depending on the availability of the device, a manual drive is used in the form of a flywheel or remote control using an electric drive.

Flanged valves for pipelines are used not only in water supply networks, but also when pumping oil products or other liquid media.

AT distribution networks on pipelines DN100 and less, valves and taps with coupling connections are often used. Such devices are less overall and technologically advanced during installation. Connections are made by screwing onto the thread of the mating part.

The tightness of such a joint is ensured by the use of various sealants: flax fiber, FUM tape (fluoroplastic sealing material), sealing cords and silicone sealant special purpose. Such a connection is less reliable than a flanged one, but the elimination of leaks on it is faster and easier.

Shut-off coupling valves for pipelines are used on in-house distribution networks with dimensions less than DN 50 at a pressure in the pipeline from 0.6 atmospheres.

Water stop valves for distribution networks

Such products of various types and purposes are designed to deliver water from the supply tank to the end point of consumption. Its main purpose is to close or open the flow of fluid in the pipeline, as well as to regulate the pressure in the network. Simply put, any of these mechanisms, be it a faucet or a valve, allows you to cut off or resume the water supply.

The device of shut-off valves is quite simple. The basis is a cast-iron or brass pipe. A valve is inserted into it, which can partially or completely block the lumen in the pipe, which leads to a change in pressure in the pipeline or a cessation of flow. The mechanism is controlled by a lever crane of arbitrary shape.

Functional purpose of devices

Fittings on the water supply network are installed not only in every house, but also in every apartment. It serves to regulate the pressure in the domestic plumbing and distribute water to all areas of the apartment, where it is provided for by the project.

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Such devices are also installed in industrial buildings and premises where the use of water is provided for by the production technology, as well as for sanitary needs. For this purpose, pipes made of special materials other than those used in residential construction are used.

Shut-off valves for water supply are functionally designed to lock the liquid in the pipe and, if necessary, supply it to the destination in the right amount.

The material for the manufacture of locking mechanisms can be various substances, but more often than others they are such as:

1. Cast iron of various modifications.
2. Brass.
3. Stainless steel, capable of painlessly passing chemically active liquids, which are also often pumped through pipelines.

On the advantages and disadvantages of various classifications of devices

Due to high performance and aesthetic appearance, brass or stainless steel gate valves are the most popular at present. Such products in water supply network can serve up to a decade and a half.

Despite this, research to improve the resistance of water fittings using new materials is ongoing. As a result, devices polymer materials, which can be operated indefinitely if disloyal methods of mechanical action are not applied to them.

Watch video - classification and types

Otherwise, at the junction with different materials, wear will be uneven. And the overall service life of the system is determined by the most rapidly wearing material.

One of the advantages plastic water pipes is the fact that they do not have threaded connections. Elements are joined by soldering on special equipment or using adhesives. Such dockings are as reliable as possible and can only be broken using brute force.

For main networks for water, they are mainly used polyethylene pipes size 820 - 1020 millimeters. They use plastic fittings for water pipes of the water supply system. Such pipes easily withstand the pressure accepted for water, in most cases, no more than 20 atmospheres.

Metal pipes are connected by the same fittings. But, since threaded connections are less reliable, sealing materials and sealants must be used.

Consider the types and classifications

There are many designs of valves and faucets for plumbing. The most popular of them are:

1. Cranes with crane box.

The flow of water through the pipe is blocked when the stem is twisted by its action on the rubber gasket, which sits on the saddle and blocks the passage. The weak point in this system is the gasket, which has to be replaced periodically. The presence of a spare gasket in the house with such taps is an objective necessity. The bodies of such cranes are made of brass, less often - of cast iron.

1. Faucets and valves with ceramic inserts

This design of plumbing valves has already become familiar due to high reliability throughput node.

Water is passed from the pipe by turning the handle at an angle of about 180 degrees. In this case, the openings in the two ceramic plates are combined, and a passage for water from water pipe. Due to the high surface strength of the plates, their wear is very slow, and the use of a supporting rubber gasket in the lower (fixed part) of the crane box provides wear compensation and tightness of the connection. Details of the crane box (and the crane itself) are made of brass.

1. Ball Valves.

As a locking element in such devices, a ball made of brass with high quality surfaces. It is processed by polishing using diamond paste and then nickel or chrome plating. The hole in the ball corresponds to the size of the passage. When the stem handle is rotated, the ball rotates 90 degrees and closes/opens the hole. Wear-resistant Teflon rings are used as seals. Not intended for pressure regulation.

In addition to these types of valves, many others are produced:

• cranes for dumping air congestion in the heating system;
• emergency pressure relief valves installed on vessels;
• valves for adjusting the pressure in the internal water supply system.

Ball valves are used to close the pipeline in emergency cases.

Technology and production methods

Manufacture of pipeline fittings is a complex technological process, which includes a number of successive actions that ensure the production of reliable and salable products.

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The technology for the production of valves for pipelines provides for the following steps:

1. Marketing on the market of relevant products in order to determine the effective (sellable) range of products.
2. Design - survey work to create models and types of efficient products both in terms of quality and manufacturing costs.
3. Development of production technology, determination of the optimal composition of equipment.
4. Development of methods for effective non-destructive control of product quality.
5. Development effective advertising its products.
6. Logistics and sales of products.

The technology for the production of valves for pipelines can be represented as follows:

1. Purchase of raw materials for production. Input quality control of raw materials and components.
2. Manufacture of blanks for the manufacture of fittings by casting from cast iron, brass and other suitable materials.
3. Heat treatment of cast blanks to give them the necessary mechanical properties.
4. Machining of working surfaces to the required parameters of flatness and surface finish. Turning threaded connections.
5. Applying a protective coating by electroplating. Nickel plating is usually applied.
6. Assembly of water fittings using parts of our own production and components purchased through cooperation.
7. Final quality control of finished products and transfer to the warehouse finished products. It should be noted that intermediate control operations during the manufacture of reinforcement are carried out after each technological step. For example, after casting and electroplating, ultrasonic testing is mandatory to detect pits and other discontinuities.
8. Sales of finished products.

Enterprises that intend to sell their products abroad need to certify them according to ISO 9001. It is important that in accordance with the requirements of this standard, not only the final result (products) is regulated, but the entire process of organizing production, starting from the document flow.

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Technical documentation

The production of valves for pipelines and oil pipelines in terms of general requirements is regulated by GOST R 53673-2009. The operating rules and features of the installation are considered by a number of SNiPs in terms of the relevant requirements.

Valves for pipelines - a range of structures installed on pipelines in order to control the transported medium by changing the actual area of ​​the pipe flow section. Technical requirements and the nomenclature of pipe fittings for industrial and domestic types are given in normative document GOST No. 52720 "Pipeline fittings".

This article presents the classification of pipeline fittings. We will consider its varieties, functional purpose, design features and study the marking of reinforcing products.

Article content

Classification of pipe fittings

According to the provisions of GOST, pipe fittings divided into groups based on the following factors:

• functional purpose;
• scope;
• device control method;
• method of connection with the pipeline;
• sealing principle.

The main classification parameter is the functional purpose, according to which the following types of pipeline fittings are distinguished:

1. Shut-off valves are structures designed to completely shut off the flow of the medium circulating through the pipeline. Shut-off products, in turn, are divided into - drain valves (used to remove the transported medium from the pipeline) and control fittings(shuts off the flow and supplies the working medium to the instrumentation).
2. Control valves - used to adjust the throughput of the pipeline. It is divided into throttle - due to an increase in hydraulic flow resistance, and shut-off and control - combines the functions of two types of fittings, the most commonly used pipe fittings today.
3. Protective (cut-off) fittings - the installation of cut-off fittings is carried out to protect the equipment connected to the pipeline and the main line itself in emergency situations. The valve closes and disconnects the failed part of the pipeline from the circulation ring, which makes it possible to produce the required repair work. A type of protective fitting is, which prevents the possibility of a reverse flow of the circulating medium.
4. Safety valves are structures that automatically release excess pressure in the system, which protects equipment and the pipeline from overload.
5. Distribution fittings - installation is carried out in two adjacent pipelines if it is necessary to combine and mix their flows.
6. - structures used for either distributing the main into several channels. This group includes all kinds, bends, crosses, etc. The material for the manufacture of connecting fittings corresponds to the material of the pipeline (the production of both steel and polypropylene and polymer products has been established).

Depending on the scope of application, all pipeline fittings are divided into industrial and domestic. Household fittings are used for gas pipelines, water pipes and heating pipes. The class of industrial fittings, in turn, is divided into the following groups:

• steam;
• water;
• oil;
• chemical;
• gas;
• food.

A separate subgroup includes ship fittings used on military and civilian ships, which have an increased reliability class.

According to the method of control, pipeline valves are divided into two types - automatic and controlled. Controlled valves can have several types of actuators:

• manual drive;
• mechanical drive (electric, pneumatic, hydraulic or electromagnetic type);
• remote drive - a control structure that is remote from the valve and is connected to it by means of a transmission (shaft, cable, gears or bearings)

Depending on the method of connection to the pipeline, pipe fittings can be:

• flanged;
• coupling;
• tsapkovoy;
• choke;
• welding.

The last classification factor is valve sealing principle, according to which the structures are divided into:

• stuffing box - at the junction of the fittings and the end part of the pipeline, glands made of asbestos, graphite, fluoroplastic or are placed;
• bellows - instead of elastic materials, metal are used for sealing;
• membrane - structures in which the membrane simultaneously performs a sealing and locking function;
• hose - a pinched rubber hose is used as a sealing material.

Marking of pipeline fittings

Marking of pipeline fittings is carried out in accordance with the provisions of GOST No. 4666-75 "Pipeline fittings". The marking consists of alternating letters and numbers, example - 30s941nzh2, where:

• 30 - type of fittings (valve);
• c - material of manufacture (carbon steel);
• 9 - drive type (electric);
• 41 - model number;
• nzh - type of sealing material (stainless steel bellows seal);
• 2 - version.

You can find the decoding of each nomenclature component of the marking in the tables of TsKBA (Central Design Bureau of Valve Building).

The principle of operation of pipeline valves (video)

Types of pipeline fittings

Shut-off pipeline valves, the most common type of valve products, have several design options execution. Pipe fittings are divided into the following types:

• shutter (disk shutter);
• valve (valve);
• tap.

In which the overlapping structure moves parallel to the movement of the circulating flow. There are two types of valves - wedge and parallel. The flow is blocked by a gate, in which the seals are placed at an angle to each other. The shutter, depending on the design, can be rigid, elastic or made in the form of two alloy steel disks.

Gate valves are divided into types according to. Designs with a rotating (not retractable) spindle are used in pipelines transporting corrosion-neutral media, where the spindle does not provoke material destruction for a long time (oil, water); in the chemical industry, it is practiced to install plugs with a retractable spindle. Powerful steel gate valves ways to endure flow pressure up to 25 MPa.

A valve is a fitting that shuts off the flow due to the reciprocating movement of the valve inside the pipeline. The valve, in most cases, has a flat shutter, the cross section of which corresponds to the inner diameter of the pipe. The valves are manufactured with a flange connection, providing high level tightness.

Depending on the material, steel (stainless steel or alloy steel) or bronze. There are linear, angle and mixing valves, the installation of the latter is carried out if it is necessary to maintain the required temperature, concentration or density of the transported medium.

Gate valve is a fitting that closes the pipeline due to rotation around its own axis of the locking disk. Dampers are structurally similar to valves, but they have much smaller dimensions and a wider scope of use - this valve, in addition to industry, is in demand in heat and water supply, sewer systems.

A faucet is the most common type of shut-off and control valves in domestic use. The locking part in the valve is placed in the direction of the flow of the circulating medium; it can be made in the form of either a conical element.

Shut-off valves can be installed on pipelines transporting liquid or gaseous media. The advantages of this armature include compact dimensions, simplicity and maintainability of the design, minimum activation time.

Depending on the type of construction, the valves can be straight, angular or (three-way), in which two inlets are connected to the central outlet, which allows mixing several working media with each other.

Gate valve, valve, ball valve - what to choose?

gate valve

In this article, the author does not aim to give complete description valves such as gate valves, butterfly valves and Ball Valves. An attempt has been made to show the advantages and disadvantages of one or another type of fittings, leaving the buyer the right to give preference to one of the considered types of fittings.
- this is a type of valve, in which the locking element moves perpendicular to the axis of the flow of the working medium reciprocating or reciprocating. The main purpose of the valve is to block the flow of the working medium with a certain degree of tightness in the valve. In some technological systems, it is permissible to use gate valves as shut-off and control valves (with a partially open gate for a short time), when discrete regulation of the flow of the working medium is possible.
According to the degree of tightness, the valves are: class A, B, C, D, B1, C1 and D1 according to GOST 9544-2005.
There are currently a large number of constructive types valves that are different:

• the design of the locking element - with a wedge locking element, a wedge gate valve or with a parallel locking element, a parallel gate valve;
• the location of the travel unit - valves with a rising stem, in which the stem thread of the spindle is located outside (in the yoke assembly), and moves along the thread of the threaded sleeve without being in contact with the working medium, and valves with a non-rising stem, in which the spindle performs only rotational movement , and its threaded part is constantly located in the internal cavity of the valve body;
• the design of the passageway - full bore (the diameter of the passage of valves is almost equal to the diameter of the pipeline), non-full bore (the diameter of the passage of valves is less than the inner diameter of the connecting flanges);
• drive type - with manual control from a flywheel, with manual control through a reducer, with an electric drive, a pneumatic drive, a hydraulic drive;
• way of connecting to the pipeline - flanged, coupling, by welding (steel valves);
• type of shaping of body parts - cast, welded;
• type of sealing of moving parts with respect to external environment- stuffing box, bellows;
• housing material: steel (non-corrosion-resistant and corrosion-resistant), cast iron.

Valve advantages:

• low hydraulic resistance with a fully open valve, which is especially valuable when using a valve on a pipeline through which a liquid medium constantly moves at high speed (main pipelines);
• absence of turns of the flow of the working medium, as, for example, with valves, which does not lead to energy losses, especially with large passage diameters;
• relatively small building length;
• the possibility of supplying the working medium in any direction;
• a wide range of standard sizes (solid wedge valves, elastic wedge valves, double disc valves, gate valves, pinch valves), which allows you to choose the most optimal type of valve for the given operating conditions.

The disadvantages of valves include:

• inability to use for media with crystallizing inclusions;
• relatively small allowable pressure drop across the gate;
• low response speed, which does not allow emergency shutdown of the medium flow in an emergency;
• the possibility of obtaining a hydraulic shock at the end of the stroke;
• the possibility of jamming of the shutter with fluctuations in the temperature of the working medium for gate valves of small diameters with a rigid wedge;
• difficulties in repairing worn sealing surfaces during operation;
• high cost of repair at a relatively low price of the valve (the cost of valve repair is 70-80% of the cost of a new valve);
• relatively large construction height and weight.

When choosing one or another type of valve, it should be remembered that each type of valve, in addition to general advantages and disadvantages, has some features and differences that you need to know and which cannot be neglected. For example, it is known that gate valves with a solid wedge have the lowest metal consumption and, as a result, weight, but at the same time, from the point of view of ensuring the tightness of the gate, they are also the most problematic. This explains the use of secondary elastic seals in gate valves with a solid wedge, which is not done in gate valves with a different type of wedge. So, for the purposes of water supply, a cast-iron valve with a rubberized wedge of the MZV (MZVG) 30ch39r type is successfully used.
For gate valves with a solid wedge, one more feature is characteristic - one-sided tightness in the gate. This seems to be a clear disadvantage. But, working on a liquid medium and being closed (in this case, a cavity filled with liquid is formed in the valve cover), not a single valve with a solid wedge, due to this drawback, will be destroyed due to an increase in fluid pressure in the cover cavity due to a change in its temperature, while valves with other wedges can break.
If for valves with a solid wedge there is a high probability of jamming of the valve when working with high temperatures working environment (300 °C and more), which requires periodic checks of its performance or the use of devices for wedging, then valves with an elastic wedge are free from this drawback.
Double-disk gate valves, on the contrary, are the most metal-intensive, but they have a high seal tightness and have better maintainability compared to wedge gate valves.
As noted above, gate valves come with non-rising and rising stems. The normal operation of the threaded pair spindle-drive nut can proceed only with the constant presence of lubrication and systematic maintenance of the structure. This is only feasible if the running unit is available for maintenance. In gate valves with a non-rising stem, the travel assembly is immersed in the working medium, access to it is closed, it is exposed to corrosion and abrasive particles of the working medium, if it is clogged, which imposes restrictions on the use of such valves. They are applicable to pipelines transporting mineral oils, oil, water, which are not clogged with solid particles and do not have corrosion signs. Since they have a shorter face-to-face length than rising stem valves, it is advisable to use them for underground utilities and wells, as a Christmas tree in oil wells.
For gate valves with a rising stem, the spindle thread and nuts are outside the valve cavity, therefore, the disadvantages noted above are not typical for them, which allows these valves to be used at critical facilities and sections of the pipeline network.

As an alternative to traditional valve types in recent times Butterfly valves and ball valves are increasingly used among shut-off valves.

butterfly valve

By its design, it is a short piece of pipe with a locking or adjustable element in the form of a disk that rotates around an axis located perpendicular to the axis of the passage. The axis of the disk is at the same time the valve stem with a stuffing box seal in the places of passage through the body. The disk may be flat or biconvex (lensed). The material used for the manufacture of discs is nickel-cast iron, chrome-cast iron. The edges of the rotary disk are lapped to the inner surface of the body. To ensure the tightness of the shutter, metal or soft (rubber, fluoroplastic) rings are used. Butterfly valves can be used as both shut-off and control valves. For use as control valves, several fixed intermediate positions are provided, for which such valves are equipped with a device that fixes the position of the rotary disk. In the open position, the disk is mounted along the axis of the body, creating minimal resistance to flow. In the closed position, the disc is installed perpendicular to the axis of the body, with its edges in contact with sealing rings, which can be located both on the disc itself and on the valve body. The valve is installed on the pipeline between the pipeline flanges, tightened with studs. Butterfly valves can be mounted in any position, however it is recommended to mount larger diameter valves in a horizontal position as the vertical installation the possibility of jamming associated with the ingress of solid particles into the stem area is not excluded. Butterfly valves can be manufactured with eccentrically mounted discs. Such an arrangement of the disk creates favorable conditions for its interaction with sealing rings, eliminates the hysteresis inherent in disks with zero eccentricity.
Butterfly valves can be operated manually, using a gearbox, using an electric drive, pneumatic drive or hydraulic drive.

The popularity of the use of butterfly valves is determined by a number of advantages over other types of valves:

• relatively low hydraulic resistance;
• short opening and closing time of the shutter (disk);
• there are no stagnant zones in which mechanical impurities and dirt can accumulate, entering the gate along with the working medium;
• the absence of threaded working pairs in the design (compared to gate valves, where a threaded pair "sleeve-spindle" is used), which increases performance when exposed to adverse environmental conditions;
• relatively small dimensions and weight;
• large passage diameters;
• a long service life subject to the rules of operation ( normative term service - 30 years);
• simplicity and ease of installation and dismantling.

The disadvantages of shutters include:

• reduced tightness of the shut-off organ;
• large torques on the shaft due to large unloaded forces acting on the disk of valves with large diameters of the passage;
• the difficulty of obtaining the calculated throughput characteristics when the shutter operates as a control damper.

Butterfly valves are commonly used in the water supply, brewing and food industries where clean media are used.
The main parameters of butterfly valves are regulated by GOST 1251-89 and GOST 25923-89.

ball valve

As well as valves, and butterfly valves are designed to be installed as a shut-off device that shuts off the flow of liquid and gaseous working media on pipelines in water and gas supply systems, at thermal power plants, in chemical, food, oil refining, gas and other industries.
Steel ball valves are considered here as an object of analysis. We are not talking about ball valves made of brass or bronze of small diameters (DN 15-50mm) used when installing plumbing equipment.
The shut-off element in a ball valve is the ball itself (a plug made in the form of a ball), which has a through hole for the passage of the working medium and is made of stainless steel.
There are two basic versions of ball valves - valves with a floating plug, when the ball is supported by sealing rings, and valves with a plug (ball) in the supports. The latter are more suitable for high pressures and large diameters. In these valves, the load from the differential pressure in the closed position is taken up by the support bearings, and not by the sealing seats. Floating ball valves are used at low pressures and temperatures.
The shutdown of the pipeline occurs when the valve lever is moved to the extreme closed position (without stopping in intermediate positions). In this case, the ball inside the crane rotates around its axis with the side in which there is no through hole for the passage of the working environment. When the valve is installed in the open position, the plug assumes a position in which the hole in the ball coincides with the axis of the pipeline, thereby ensuring the passage of the working medium.

Advantages of ball valves:

• high degree of tightness (as a rule, tightness class "A");
• low hydraulic resistance;
• small weight and dimensions;
• short opening and closing times;
• maintenance is not required during operation (pull-ups, lubrication, etc.);
• a large “line” of valves by operating parameters (nominal passage diameter, pressure, temperature), by installation method (“flanged”, “coupling”, “for welding”), by type of execution (all-welded body or collapsible body).

So, for example, BREEZE steel ball valves, manufactured by the Olbrizservice plant (Ukraine, Kyiv) are presented in two types of execution: the EUROPE series - in an all-welded body, the SILVER series - in a collapsible body. Valves are supplied in three connection modifications: WELDING, FLANGE, THREAD. The range of diameters of BREEZE valves of various modifications is from 15 to 300 mm, working pressure is 1.6, 2.5 or 4.0 MPa, working temperature is from minus 30 to 200 °C. The plant produces two types of valves 11s33p and 11s41p with flange connection, in which the construction length is equal to the construction length of steel valves common in operation, such as 30s41nzh, which makes it possible to easily replace failed valves with cranes. Extended stem valves are available for underground installation.

At the enterprise Lugansk plant of pipeline fittings "Spetsavtomatika" through the Trading House "MARSHAL" you can order ball valves widely known to the buyer, manufactured under the trademark "MARSHAL": from carbon steel or corrosion-resistant steel, welded collapsible or all-welded non-collapsible, cast collapsible or cast non-collapsible , short or non-short, flanged, socket or weld end, full bore or full bore, unpowered, geared or driven (electric, pneumatic, hydraulic).

To select a particular crane, you need to know a certain minimum of characteristics, which, as a rule, are indicated in the passports for the product.
As an example, below is a list of technical characteristics indicated in the passport for the MARSHAL 11s67pSF ball valve:
Nominal diameter…………………………………….200 mm (250,300, 350,400,500,600mm)
Working pressure, no more…………………………..1.6 MPa; (2.5Mpa;4.0Mpa)
Operating environment temperature………………………….from -40 °C to 180 °C
Working environment………………………………………….water, gas, oil products and other non-aggressive media, neutral to the materials of the crane parts
Tightness class………………………………….A GOST 9544-2005
Climatic version…………………………..U1, HL1 GOST15150
Ambient temperature…………….not lower than - 40 °C (U1), not lower than - 40 °C (ХЛ1)
Number of working cycles…………………………..not less than 10 000
Full service life………………………………….not less than 10 years
Connection to the pipeline………………………..flange
Management…………………………………………….gear
The valves are manufactured in accordance with GOST28343 (ISO7121)
Building lengths………………………………….GOST 28908, GOST3706 (ISO5702)
Flange size………………………………………..GOST12815 (ISO7005).

Along with the advantages, ball valves have a number of disadvantages that must be considered when choosing fittings.
Disadvantages of ball valves:

• the impossibility of using standard ball valves as control and throttle valves;
• increased requirements for the cleanliness of the working medium passing through the valve, especially for the presence of solid particles;
• possible “sticking” of the ball during long-term operation in the closed or open position;

Thus, after passing brief analysis modern locking devices, it can be concluded that each of the considered types of valves has certain advantages and disadvantages, knowing which you can best determine the choice of valves for the specified requirements and operating conditions.

Shut-off valves are a type of pipeline valves that perform the function of shutting off the flow of a liquid (water, gas or any other fluid). This type of reinforcement is characterized by a wide distribution - about 80% of the total number of parts used. Test and bleed and control and bleed valves used to control the level of liquid (water, gas or any other fluid) in tanks, sampling, expelling air from upper cavities, drainage, etc. - also types of shut-off valves.

The material for the manufacture of these parts can only be ductile iron or stainless steel. This is due to the fact that inner surface valves are constantly in contact with water, steam, gas, oils and other chemically active media - however, metal corrosion in this case is categorically unacceptable due to the fact that if the integrity of the wall is damaged, the medium will leak.

Important! Due to its functionality, valves have found application in a variety of areas of production.

Depending on the area of ​​​​use, it can be divided into two types:

1. Shut-off valves, which are used in special conditions (“narrow profile” use);
2. Shut-off valves with some general technical application;

Examples of full-opening shut-off valves are plug valves, valves, valves with a through channel, which has the structure of a Venturi tube.

Important!!! What types of parts are used the most?

Cork faucet

Production reached its maximum volumes in industrial scale the following parts from the category of shut-off valves:

1. Cranes,
2. Valves (valves),
3. gate valves
4. dampers.

Brief description of each type of part

It should immediately be noted one distinctive feature of shut-off valves - their dimensions do not exceed 300 mm in the diameter of the passage. These parts are applicable exclusively in dead-end sections of the liquid supply system (water, gas or any other fluid). In addition, they can also be used for spindle bellows seals.

In addition to this variety of parts, the so-called ball valves and dampers of a simple design have gained recognition among hydraulic masters due to their reliability and multifunctionality.

An important advantage of gate valves is their relatively simple structure: short length, low hydraulic resistance. They are classified into two types: parallel two-disk and wedge. In the event that the pressure exerted by a liquid or gaseous medium is negligible, then double-disk valves should be used, high pressure necessitates the installation of wedges (the wedge itself can be solid, elastic or composite).

Detailed characteristics of cranes. Their classification, functional characteristics and scope.

It is difficult to even imagine how wide the scope of their application is - pipelines, water pipelines, steam pipelines and gas pipelines are necessarily equipped with these parts. As a rule, taps with small dimensions and low resistance are used. The mass of this kind of part is from 0.881 kg to 8.64 kg. Diameter d in inches from one to three.

According to another classification (structural), the following types of valves are most often used: plug and ball. They, in turn, are divided into tension and stuffing boxes (the main criterion for the difference is the way they are sealed). Connection to the pipeline is carried out using a coupling, flange or welding. Plug valves (gas, coupling, cast iron) have found application on pipelines through which natural gas. Attachment is carried out using a threaded coupling. It should be noted that the normal functioning of these types of cranes is possible with the following indicators: working pressure - Pp=0.1 MPa, tp< 50°С.

Another type of cranes is stuffing box (coupling cast iron). They are necessary on pipelines, through which the transit of water or oil is carried out. The required temperature for successful operation is tp< 100°С. Особенности строения заключаются в том, что основные детали крана (корпус, пробка, сальник, заполненный пенькой или резиной) сделаны из чугуна.

In the event that it is necessary to install a valve on a large diameter pipeline, you should opt for a ball valve that has small dimensions, low resistance and high quality. If a gas or liquid (water, or any other fluid) will be supplied over a wide temperature range through the same pipeline, it is necessary to use a flanged steel valve with lubrication or with nozzles for welding. It can be controlled both remotely and manually, using a flywheel.

control valve

Detailed characteristics of shut-off valves. How are they divided, what do they consist of, what is the scope of their application?

In this case, as a rule, devices (valves) with remote control or with flywheel control are used.
The choice of the valve is based on the temperature of the liquid or gas that will be transported through the pipeline.

1. In the event that it is intended to transport water (gas or any other fluid), the temperature of which does not exceed 50 ° C, it makes sense to install cast-iron shut-off coupling valves.
2. If the temperature of the transported will be in the range strictly from 45 to 50 degrees Celsius, then it makes sense to use shut-off valves with an electromagnetic drive, which can be controlled manually, since they work from an electromagnetic drive.

The main functions and structural features that characterize dampers

The use of these parts is justified only if the diameter of the pipeline is about 2200 mm. These parts are characterized by a number of very advantageous advantages:

1. The maximum possible simplicity of the device, in which, as always, it shows the greatest efficiency.
2. They are easy to manage.
3. Their price is quite acceptable and weight. As a rule, dampers are controlled manually, however, reinforced dampers are sometimes produced using a hydraulic or pneumatic actuator. An important point - remote control is possible only in the case of dampers with a diameter of 300-1600 mm at Ru = 1.0 MPa.
4. Very rarely repairs are needed.

How is a damper different from a valve, which is used much more?

Considering that dampers are, by definition, short devices and their use is justified only on highways and technological productions. The structure of the valves implies the presence of a movable or immovable spindle. In fact, it is for this reason that there are different types valves. Naturally, their repair also depends on the type.

In the event that the spindle is movable, then such valves can be electrically driven. Wedge gate valves have a fixed, flanged, cast-iron spindle. Naturally, thanks to this, they are characterized by remote control.

The use of two-disk gate valves with a fixed stem made of cast iron is justified in the event that fuel gas or water with a temperature reaching 100 ° C is transported through the pipeline.

If fuels and lubricants are being transported, then it is necessary to install steel valves so that they do not have to be constantly repaired.

What fittings are needed when working with aggressive media?

All valves that are applicable in the case of transporting substances that are in themselves an aggressive environment, without bringing them to a temperature, are subject to exactly the same classification, but with a slight difference - it is divided into the following types: taps, valves, gate valves.

The most common shut-off devices will be: diaphragm valves, ball valves, hose valves, but the most famous and frequently used are stainless steel bellows shut-off valves (if used, repairs to these parts are almost never required).

But just the gate valves, on the contrary, have not gained popularity in the Russian Federation (namely, when transporting aggressive media through the pipeline), for a number of reasons, one of which is the repair that these parts will constantly need during such operation.

So it turns out that in the vast majority of metallurgical enterprises that are successfully operating in our country, the most common chemically aggressive substance is sulfuric acid. It is precisely this that is supplied through the pipeline and provides a continuous process for the production of steel and many other alloys, for which it received the second name - the bread of ferrous metallurgy. So the impact of this particular substance has become the most common reason for the need to repair installed valves.

findings

The use of various elements of valves is necessary for the normal functioning of any pipeline, regardless of what is supplied through it - be it gas, water or some other chemically active liquid. By controlling the elements of the shut-off valves (this happens both manually and automatically), it is possible to regulate the pressure in the system. Thanks to advanced technologies, a large number of the most diverse elements of shutoff valves (valves, taps, gate valves, dampers) have already been designed, each of which ideally performs a particular function. There are images in the photo above various parts, which are already installed in the pipeline (or just manufactured) and thanks to them, the safe control of the entire fluid supply system is ensured.

You may be interested in:

Federal Agency for Education

State educational institution higher

vocational education

"Ufa State Oil Technical University"

Department: "Transport and storage of oil and gas"

Test

on the topic: "Types of valves, its purpose and design"

Completed by: student of group GRz-07-02

Politaev M.A.

Checked by: teacher

Fazletdinov R.A.

Shut-off valves - designed to completely shut off the flow of the working medium in the pipeline and start the medium, depending on the requirements of the technological process ("open-closed" cycle). These include gate valves, taps, shut-off valves, butterfly valves. The main purpose of shut-off and control valves is to block the flow of the working medium through the pipeline and re-start the medium, as well as to ensure the necessary tightness. The plant of pipeline fittings monitors the quality of its products. Fittings are installed on pipelines of high and low pressure, units and vessels. The shut-off valves are designed to control: water, gaseous, vaporous, gas-liquid mass, by changing the area of ​​the diameter of the flow section of the hole. It must provide a reliable and complete overlap of the flow section. In principle, it should provide only two states - open or closed - and may not be intended for operation in an intermediate position of the working body.

According to their functional purpose, pipeline fittings are divided into the following main classes:

Shut-off - designed to shut off the flow of the working medium with a certain tightness;

Regulating - designed to control the flow by changing the amount of the working medium flowing through the pipeline. Control valves are controlled from an external energy source;

Distribution - designed to distribute the flow of the working medium in certain directions or to mix flows;

Safety - designed for automatic protection equipment and pipelines from unacceptable excess pressure by dumping excess working medium., protective (cut-off) designed to automatically protect equipment and pipelines from unacceptable or unforeseen changes in the parameters or direction of the flow of the working medium by the technological process, as well as to turn off the flow.

Phase separation - designed for automatic separation of working media depending on their phase and state. These include steam traps, air vents and oil separators.

A gate valve is one of the shutoff valves. Here, unlike taps, the locking element does not perform a rotational movement, but a reciprocating one. The movement of the locking element occurs perpendicular to the movement of the liquid.

Chronologically, gate valves appeared among the first of the devices for blocking the water flow. This is due to their sufficient simplicity and unpretentiousness in operation and repair. At present, due to the rapid development of technology and technological processes, valves are increasingly being replaced when laying pipelines by water shut-off devices with a circular movement of the actuating element. Gate valves, like shut-off valves, are mainly used in two modes: open and closed, i.e. when the shut-off element is in its extreme positions. When using the valve in an intermediate position, it is destroyed working surface due to vibration caused by high frequency movement executive body along and across the flow of a liquid as it moves through a pipeline. The fastening elements of the actuating element are also loosened. As a result, the valve fails ahead of schedule.

Gate valves are divided into several types. Wedge, parallel, rising and non-rising stem. They are used at pressures from 2 to 200 atmospheres. Nominal diameter from 8 mm to 2 m.

Figure 1 Gate valve ZMS-65-14 K1 HL (Baku)

Table 1 Specifications gate valves ZMS-65-14 K1 HL

Xmas tree valves are designed to seal wellheads, control and regulate their operation, as well as to carry out various technological operations in temperate and cold macroclimatic regions for environments containing CO2, H2S, and produced water. It is assembled according to the schemes of tee and cross types in accordance with GOST 13846 - 84.

The following designations are used in the X-mas tree code: AF - X-mas tree; design according to the schemes of GOST 13846 - 84; a - double-row concentric suspension of lifting pipes; K – suspension of the lifting string on the thread of the pipe head sub (the letter is not written on the coupling suspension); E - for the operation of wells with ESP; B - valve control method (remote and automatic); the first number is the diameter of the conditional passage along the barrel and side strings in mm; the second number is the working pressure; HL - climatic version for a cold region; version for corrosion resistance: K1 - for environments containing CO2 up to 6%; K2 - for environments containing CO2 up to 6%; K3 - the same, H2S and CO2 up to 25%; K2I - for X-mas trees made of low-alloy and low-carbon steel, using an inhibitor in the well.

The fittings include a pipe head, a Christmas tree, locking devices with manual and pneumatic control, chokes.

The pipe head is designed for hanging one or two rows of tubing, sealing them, as well as for performing technological operations during well development, operation and workover.

The columns of lifting pipes are suspended on a thread and on a coupling suspension.

Suspension of columns on the thread is carried out: with a single-row elevator - on the thread of the stem coil; with a two-row lift: the inner column is on the thread of the stem coil, the outer one is on the thread of the tee (cross) of the tube head.

Suspension of columns on a coupling suspension is carried out: with a single-row elevator - on a coupling in the crosspiece of the pipe head; with a two-row lift: internal - on the sleeve in the tee of the pipe head, external - on the sleeve in the cross.

Figure 2 X-mas tree AFK 1 E65x21M K1 HL

(for ESP, RPM and fountain wells)

The tree is intended for directing well production to the flow line for operating mode control, for installing special devices, when lowering downhole tools or pigs for cleaning pipes from paraffin, measuring the pressure and temperature of the medium, as well as for carrying out some technological operations.

As locking devices for X-mas trees, plug valves and direct-flow valves with forced or automatic lubrication are used. They are designed to cover the passage holes in the X-mas tree and wellhead equipment.

Table 2 Technical characteristics of X-mas tree fittings AFK 1 E65x21M K1 HL

Adjustable or non-adjustable chokes with a replaceable sleeve made of wear-resistant material are installed on the side strings of the Christmas tree to control the operating mode.

Christmas trees are classified according to their structural and strength characteristics:

Working pressure (7, 14, 21, 35, 70, 105 MPa);

Execution scheme (6 schemes);

The number of rows of pipes lowered into the well;

Designs of locking devices;

The dimensions of the flow section along the wellbore (50-150 mm) and side outlets (50-100 mm).

All X-mas trees are used with column heads OOK1 10"" ´ 9 5/8 ´ 6 5/8 - 210 or a column head designed by TsNIL "" GANG "".

Column heads, like casing pipes, are an integral part of the well design as an engineering structure. They are designed for hanging another casing string, sealing and controlling pressure in the annular space between adjacent pipe strings.

Figure 3 Tying column head OKK1-35 K1 HL

The design of the string head, X-mas tree, their piping scheme should provide optimal well operation modes, sealing of the pipe, annulus and annular space, the possibility of technological operations at the well, deep research, sampling and control of wellhead pressure and temperature.

The operating conditions of the casing head are quite difficult: the load from the weight of casing strings can exceed several hundred kilonewtons in deep wells. Elements of the column head also perceive the pressure of the medium in contact with them. Violation of the reliability of the string head inevitably leads to serious accidents, damage environment, and in some cases may cause fires, explosions, accidents.

Figure 4 Rotary shutter

Gate - an element of pipeline shut-off valves, where the regulating (shut-off) body rotates around an axis that is not its own axis. The most common type of this type of pipe fittings is a butterfly valve, in which the regulating element is made in the form of a disk.

In terms of ensuring the tightness of shutting off the flow of liquid, butterfly valves can be with a metal-to-metal seal, with a soft saddle seal, with a Teflon coating of the blocking parts of the valve. According to the type of its connection with the water (pipe) wire system, the valves come with flanges for welding and for threaded connection.

The control of the shutter, depending on the effort required to bring its moving part to its working position, can be simply by means of a handle, through a gearbox, by means of a pneumatic or electric drive. The material and design of the shutter must be such that it can work for the prescribed period not only to open and close the substance passing through it, but also to regulate the passing volume. For this, the bolt handle is most often made with a latch that allows you to lock the handle in various angular positions.

Such operational properties of valves as convenience and simplicity of their installation and replacement of sealing elements, sufficient durability (up to 100 thousand openings and closings), relatively low cost led to their widespread use in the pipeline industry.

Figure 5 Shut-off valve

Shut-off valve - one of the types of shut-off equipment. Can be made from various materials: steel, brass, some kind of plastic, etc. But they all have the same device - the body and the locking element. The locking element can be made in the form of a cylinder (cylindrical valve) or in the form of a ball (ball). Less often in everyday life you can find a tap with a conical locking device.

In terms of performance, shut-off valves can be full bore or semi-portable. Semi-through valve - if the opening to be closed is smaller in diameter than the diameter of the pipes connected to the inlet and outlet. And accordingly full bore - when it is the same.

The main task of a stopcock is to block the flow of fluid passing through it. That is, he has two working positions - open and closed. It is clear that if the faucet handle is turned not by 90 degrees, but, say, by 45, then the flow of the passing fluid can be reduced, roughly speaking, by 2 times. Thus, smoothly changing the angle of rotation of the handle, you can smoothly change the flow. However, this is not recommended, because depending on the pressure and composition of the liquid, the shut-off valve may be damaged, especially the sharp edges of the valve structure, which can be worn off, resulting in full coverage liquid may continue to ooze at the outlet of the faucet.

Shut-off valves are used both in industry (for transporting water, oil products, gas), and in everyday life, to block, if necessary, various parts of the water supply.

Figure 6 Valve

Valves. This is another class of valve devices. Here the locking element is on the spindle. The rotational movement in one direction or another of the spindle (using a simple flywheel or any devices) is converted into a reciprocating movement of the locking element, which regulates the flow of fluid passing through it. The spindle is rotated either manually (if the force is small) or using some kind of electric (hydraulic) motor.

The mass consumer is most familiar with this type of stop valves in everyday life, since various modifications of valves can be found in any apartment, on suburban area, in various public places, etc.

The most common type of valve is a straight-through valve, which is installed on straight sections of the pipeline. The main disadvantage is a rather high hydraulic resistance and, as a result, the presence of a liquid stagnation zone in the area where such a valve is installed. This disadvantage is devoid of a direct-flow valve used in those places of the pipeline where it is not allowed to reduce the flow of liquid at the outlet of the valve.

Also, the most common types of valves are angular (connects two mutually perpendicular parts of the pipeline) and mixing (two fluid flows are mixed in order, for example, to maintain a given temperature).

Figure 7 Combined multifunctional valve type KKM

The combined multifunctional valve KKM-89x21 is intended for installation instead of check valve in the layout of the tubing string during oil production by electric submersible pumps (ESP)

Table 3 Technical characteristics of KKM

Valves perform in pipe fittings the role of a kind of sensors combined with an actuator.

The main type are safety valves that automatically release (to the atmosphere or into special containers) excess liquid or gas (steam) from the pipeline when a pressure in it exceeds the allowable technical parameters, thereby preventing a pipeline failure. According to the type of actuator, they can be spring and lever-load.

Control, bypass, distribution, mixing, shut-off valves are also used, the purpose of which is easy to determine from their name.

Shut-off valves stop the flow of liquid or gas into the pipeline, starting from some section of it, when it is not allowed to flow (for example, when a pipe breaks).

The bypass valve maintains a given pressure in a certain section of the pipeline chain by partially opening and bypassing excess liquid or gas into another branch of the pipeline.

Distribution valves (three-way or multi-way) distribute the flow of the working medium to various sections of the pipeline, more often from the control panel, and therefore they often have an electromagnetic drive.

Mixing valves are used when it is necessary to mix different media having both different temperature and different composition. Such valves are required to maintain a constant composition or temperature (or both).

Control valves. Their task is to regulate the flow of the medium flowing through the pipeline (liquid, gas). They are usually managed by external source energy.

Bibliography

1. Oilfield Engineer's Handbook

2. Shurov V.A. "Equipment and technology of oil production" M. Nedra, 1983

3. Boyko V.S. “Development and exploitation of oil fields” M. Nedra, 1990.

4. Catalogs of manufacturers of oil-producing equipment

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