Pipe fittings are used in the installation of systems, transporting various substances and depending on the purpose is divided into safety, locking, regulatory, diversion, etc.. It is also indispensable, if network repair is required. Shut-off valves are designed to change the intensity of the flow of the medium (money, liquids, petroleum products, gas, etc.) or its overlap. Such products include valves, cranes, valves, shutters and latches.
Shut-off valves are an important element of any pipeline
The main types of pipeline fittings
Pipe fittings are generally divided into the following types:
- locking;
- precautionary;
- regulatory;
- locking and regulating;
- the reverse;
- non-rotatable;
- distribution and mixing;
- non-rotatable;
- spuskna (drainage);
- phazorozdilna;
- diversion;
- protective (disables);
- reduction (throttle);
- control.
Shut-off pipe fittings are used for overlapping with the established tightness of flows of the working environment, if the network is being repaired. The main purpose of safety elements is the automatic protection of ducts and equipment from unacceptable excess pressure by discharging excess media, regulatory - adjusting the parameters of the environment by changing the cost.
pay attention! Pipeline shut-off valves combine the functions of the respective types of products.
Automatic reverse flow prevention is provided by reverse elements. Subspecies of such fittings for pipelines are return-shut-off and non-return-controlled products. The first of them may be forcibly closed, and in the second - forced restriction of the course, closing and opening.
The size and type of fittings is selected depending on the purpose and size of the pipeline
Drainage (drains) elements are pipeline shut-off valves, which is intended for discharge from tanks or systems of the working environment. If the latter is in different phase states, then the delimitation is performed using phase-separating products. Reducing pipe fittings reduce the operating pressure in the system by increasing the flow resistance of the hydraulic part.
Features of industrial pipeline fittings
Because pipe fittings as a finished product must meet all regulatory documents and safety requirements, its production is often established by large enterprises. The industrial scope of the elements requires an automatic mode of operation, remote control capabilities and a high degree of reliability. Such shut-off valves can be divided into 5 types:
- general technical purpose;
- for use in special conditions;
- special industrial;
- transport and shipping;
- plumbing industrial.
The first type of products is often mass-produced and suitable for use in any field. Industrial fittings of the second type are used in energy systems, have high technological characteristics, and, when installing or repairing transport channels for toxic and aggressive environments.
Ship and transport elements are highly demanding. Their production takes into account the mass, product dimensions and other parameters, as well as the possibility of their use in different climatic zones. Special industrial fittings are designed and manufactured to order by individual departments and enterprises.
To fittings for pipelines, transporting aggressive working environments, increased requirements
Production of elements
Ductile iron is used for the production of shut-off valves, if the pressure of the medium in the channel is not more 1600 kPa or steel, if the pressure exceeds the specified value.
pay attention! Its production is carried out on high-quality and high-precision equipment, located on the area at least 300 m2. It is not always available over-the-counter.
The production of elements for pipelines requires the presence of such units and tools:
- furnaces;
- special press;
- machine for diagnostics;
- assembly table;
- drilling and lathe;
- belt conveyor;
- air compressor for painting;
- various other small tools.
Repair and maintenance of small diameter channels is possible thanks to the locking equipment, whose production is based on the use of high quality copper and bronze alloys. They prevent the destruction of elements from corrosion and "sticking" of the mechanism to the surface of the housing.
Types of locking mechanisms
Shut-off pipe fittings are represented by latches, valves (valves), cranes, shutters. Such a mechanism is called a latch, in which the movement of the regulating and locking element is perpendicular to the axis of movement of the working medium, at the valve or the valve - parallel to an axis of a stream.
The production of valves is based on the production of shut-off products, the diameter of the passage of which is up to 30 div. They are most often used in the end areas, when repairing the channel. The taps have an element of locking or adjustment, most often has the form of part or full body of rotation, rotates around its axis, which is located in relation to the direction of movement of the medium arbitrarily.
One of the types of shut-off valves are latches, they come with automatic control
Latches are characterized by short length and low hydraulic resistance. They are wedge with a component, elastic or solid wedge and parallel: single-disc (sliding) and two-disc. The latter type of valves is used in pipelines with low pressure.
The shutters are characterized by a disc-shaped shape of the locking or regulating element, which rotates around the axis, located perpendicular or at an angle to the flow of the working medium.
Latch as a locking element
Latches are mainly used as shut-off valves and, usually, are not intended to regulate the flow of the environment. During operation, the locking element is set to the extreme positions (closed, open). The production of latches is usually based on the manufacture of full-length structures, when there is no narrowing of the diameters of the holes in the connecting pipes.
pay attention! Such mechanisms are especially valuable for use in main pipelines, which are characterized by constant high-speed motion of the medium.
Their device provides a retractable or non-retractable spindle. Of the disadvantages of the latches are:
- long procedure of closing and opening;
- fairly high building height (elements with a retractable spindle);
- rapid wear of the sealing surfaces of the shutter and housing.
The disadvantage of latches with manual control is the long procedure of opening and closing
The industrial use of latches is very limited. Their main characteristics are: temperature threshold - up to 450 ?WITH, withstands pressure - to 25 thousand. kPa, possible diameter of the passage - from 5 to 120 div. Oil can act as a working medium, pair, oil, acid, meadow, water, etc.
Overview of types of latches
The sliding latch differs from usual execution of a closing element. It uses a metal wedge, which is able to cut inclusions in the environment, flowing inside the body of the mechanism. This type of fittings is used for pipelines with fecal effluents, pulp and paper, etc..
The wedge latch is installed on the networks of channels to lock the flow of the medium, if they are repaired. Its design includes a cast iron body, rotating spindle, which is connected to the wedge. Stamped wedge valves are used on pipelines, transporting gaseous and liquid media are neutral to the material of manufacture of the main parts of the mechanism. Their body and cover are obtained by welding individual elements, made of corrosion-resistant or carbon steel sheet.
You can control the valves as electric drives (hydraulic, electric, sometimes pneumatic), and manually. In the latter case, with a large diameter of the element requires the installation of a special reducer to reduce the effort to open / close.
Sliding valves are used for sewerage systems, inside which there is a steel wedge
It is also possible to repair cast iron and steel valves. The first type can withstand temperatures up to 225 ?WITH. On the vertical pipeline the pig-iron latch is put flat, so that the spindle is turned horizontally, and on the horizontal - flywheel up, the spindle is located vertically.
Terms of use and types of valves
Valves are devices, which are installed on the pipeline or vessel and are intended for closing or opening at occurrence of certain conditions, example, changes in the direction of flow of the medium in the channel, increase in pressure. They are single-seater and double-seater, the latter are more often used as regulating and distributive.
According to the direction of flow through the valve, such fittings are divided into angular (the outlet flow is perpendicular to the inlet flow), checkpoint (the direction of flow at the outlet and inlet is the same) and direct current (checkpoint, in which the flow line is directed). To completely block the flow of the medium in the channel, as well as its launch, based on the requirements of the technological process, which is served by such a pipeline, a shut-off valve is used. It provides good tightness both in relation to external conditions, and in the shutter.
pay attention! The non-return valve is installed on the pipeline in order to exclude the movement of gas or liquid in the opposite direction in case of breakage or leakage from the channel, or turning off the pump.
Shut-off and control valves allow you to control the flow of the working environment of the pipeline
There are also regulatory (provide control of environmental costs by changing the cross-sectional size) and shut-off and control valves, combining 2 functions. The advantages of such mechanisms include the possibility of use in vacuum, aggressive and corrosive environment, at high pressures and temperatures, easy repair and maintenance.
Device and classification of cranes
The valve may be a shut-off valve, regulating or distributive mechanism and is designed to work with liquids (y t. h. viscous) and gaseous media. For repair of pipeline fittings of this type knowledge of its design and special skills is necessary. The main parts of the crane are the shutter (Cork) in the form of a ball, cone or cylinder with through hole and housing. Brass is used to make the elements, bronze, cast iron, steel, and for aggressive environments - porcelain, plastic, etc.. d.
Classification of cranes is carried out on the following grounds:
- flow direction and number of nozzles: checkpoints, three-way, angular, multi-way;
- the nature of the shutter movement: with wringing (rise) or with rotation (without lifting) prison;
- drive type: with hydro-, pneumatic, electric drive, manual;
- form of imprisonment: needle, spherical, conical, cylindrical;
- sealing method: tension, stuffing box.
The valve is controlled by rotating the shutter. At full closure of the medium the angle of rotation is 90 degrees, at lower values there is a partial overlap of the flow and the device can be used as a control mechanism.
The usual ball valve can be found in almost every house and apartment
Features of the use of shutters
The rotary disk shutter is used for heating, pair, water supply, non-aggressive environments, petrochemistry. Species diversity of mechanisms is also represented by elements with electric drive and steel devices. The last type, based on operating conditions, can be made of carbon, alloy or stainless steel.
Such shutters, unlike cast iron, designed to work in more difficult conditions:
- the minimum value of ambient temperature: from -60 degrees;
- ambient temperature (working): to +700 degrees;
- work in an aggressive environment.
The use of steel allows you to install valves on high pressure pipelines (to 100 kgf / cm2). The main advantages of such rotary mechanisms are:
- easy installation and repair;
- possibility of installation in limited conditions;
- light weight and length (compared to the latch);
- easy replacement of the control cuff (its resource is tens of thousands of closing / opening cycles);
- cost affordability;
- jamming and prikipanie after long operation are excluded.
Another type of shutter - flange, which consists of a housing with a seal, disk and flange with seal.
pay attention! A protective composition is always applied to the body of the mechanism, which increases the service life of the product.
Control of rotary disk elements is provided by the handle (with / without retainer), reducer, electrical, pneumatic and hydraulic.
Shut-off valves are required, if the service of pipelines is performed, their construction or planned, systematic repairs. A variety of types of elements, whose production is based on their functions and features of use, large enough and represented by many manufacturers.