The term "shut-off valve" means devices that control the flow of a medium strength.In most valving elements present on pipes.Then we will understand that, what kind of divided armature what it is and where to apply.
Stop valves on pipelines used to control the flow of liquids or gases.It is able to regulate the flow in piping systems from a minimum to reduce supply to the complete standstill.
Certain types of equipment:
- cast iron valves;
- control valves;
- cranes;
- butterfly valves.
Scope
All these products are widely used in engineering systems, and can be made for general technical applications and for working in special conditions.If the valve is used only for the complete shut-off, the shut-off adjustable valves (valves and taps) can not only block the flow, but also to regulate its intensity.
device
All closures have a similar structure.This is a closed sealed enclosure in which the unit is located valves.In case there are two most frequently (in some cases more) end, by which it is firmly attached to the conduit.Assignment locking unit - a hermetic separation of the pipeline system.In its structure there are the saddle and the locking body is constantly in contact on the sealing surfaces.
Cranes
cranes are used for installation in pipelines with water, steam and gas carriers.They are characterized by a compact size (1.9 kg) and low resistance.The diameter of the crane can be 1 to 3 inches.The most common types of valves such as ball and plug.In accordance with the method they are sealing gland and tension.
tap Connection with the pipeline is done by flange couplings or by welding thereto.On the gas pipeline gas coupling used cranes.The material is cast for them.To ensure the connection of the pipeline with a crane requires the nut.Gas valves are designed to work under pressure of 0.1 MPa and temperatures up to 50 ° C.
withstand higher loads gland nut taps.They serve pipelines and aqueducts, their main parts are made of cast iron.This gland cast iron packed with rubber or hemp.Such valves are capable of operating at pressures up to 1 MPa and can withstand temperatures up to 100 ° C.
The smallest sizes are ball valves.This equipment is famous for its high quality of work, which explains its use in large diameter pipelines.They are made of cast iron, and the O-rings are made of PTFE-4.The operating parameters correspond to the characteristics of ball valves gland nut taps.
with a flange attached to the pipeline flange steel cranes.If the valve is large, it is provided with a worm gear.To regulate the flow in a faucet is the flywheel.This equipment is used for pipelines operating at temperatures ranging from -40 ° C to +70 ° C.These valves are mounted only vertically.The control can be both remote and through the flywheel.
Stop valves
Valves play a critical role in a large number of pipeline networks of regulators.This is the most common valves.What is it you can see in the picture.
's details that have the bolt, having the form of a cone or a flat plate form, which moves parallel to the axis of the sealing surface of the seat body reciprocating or arc.
valve - a kind of valve movement of the shutter is carried out by means of a threaded pair.
most common stop valves installed on pipes.Adjustment occurs in them manually using a hand wheel or remotely via the actuator.
strength of the seal is provided by rings made of leather, rubber or PTFE-4.Shut-off valves are used in pipes, the working environment which are air, steam or water.To connect to a pipe used the nut.To fill the gland used asbestos packing AP-31 - the cord of woven asbestos yarn impregnated with anti-friction.
in the water with a water temperature of less than 50 ° C install shut-off valves coupling.This equipment is able to work in any position.The water flows under the disc.The housing is cast iron, gaskets - paronitovye, the O-ring is made of leather, and the packing - asbestos.
in the pipeline for the transport of air or water is heated to a temperature of Wednesday +45 ° C.In such engineering networks permitted use in an electromagnetic shut-off valve actuator.It is designed to operate at temperatures up to +50 ° C.It has to be directed upwards.The housing unit - cast iron.Thus the spool and the cover are made of steel.This valve is controlled manually or remotely.
Dampers Dampers are designed for use in large diameter pipelines.They are installed in air-conditioning and ventilation systems at low pressures and low requirements to tightness.
Depending on the number of plates used dampers are single and mnogostvorchatymi.For liquid media flap hardly used, because they can not adequately ensure the integrity of overlapping passes.For gas dampers are used quite often.This contributes to the ease and reliability of the design.Appointment throttle - regulation and flow off.
Also a simple device management, and they have a relatively low price and low weight.Perhaps Equipment flaps hydraulically actuated pneumatically or electrically.
on pipes transporting water, are placed wafer damper pressure of 1.0 MPa.Sealing occurs by means of a rubber ring, mounted in the groove of the disc.The housing consists of cast iron products, and the rotary shaft is made of steel.
flaps controlled by the electric drive, the electric drive is mounted up.Wherein the drive shaft is positioned vertically.The dampers that are controlled manually, can be installed in any position.
compound gates to the pipeline going through the flanges.Another way to connect a welding.Operating pressure valves - 1 MPa.You can control them with the help of electric drive.
diameter valves using this electric range from 200-1200 mm.Their capacity up to 5 kW.The time that is spent on the valve opening or closing, is about fifteen minutes.
Closures
disc butterfly valves needed to control the pressure and flow of the medium.Working environment for the shutter are water and gas.They operate at a pressure of 1.6 MPa and a temperature of from -15 ° C to 200 ° C.
butterfly valves Disc belongs to Valves.When in the closed position, it enables to achieve a seal.The advantage of the bolt is its low construction length and height.The product is used in heating systems, water supply and food industries.
Catches
placed in engineering networks and other valves.What is this "gate" - a type of pipe fittings?
Valve - a representative of valves having a valve in the form of a wedge, disc or sheet, which moves along the sealing rings seat body.Wherein fluid flow is perpendicular to move the shutter.The diameter of the sealing rings may be smaller than the pipe diameter, and can be equal to it.In the first case referred to the narrowed valve, the second - a checkpoint.
In accordance with the shape of the gate valve is divided into parallel and wedge.
These products are used on production lines and trunk pipelines.Spindle valves can be non-sliding or retractable.To close or open the passage, the spindle has to make a lot of turns.Therefore, these valves are provided with electric remote control.Gate valves are non-rising stem made of cast iron.Their pressure is 0.25 MPa.The diameter of the valve - from 800 to 2000 mm, weight up to 14 tons.
valves Benefits:
- not required to overcome the pressure of the fluid motion of the working body;
- direct fluid flow, which allows to minimize on-state resistance;
- symmetrical design.
valves Disadvantages:
- strong friction during movement of the working body of the valve;
- large construction height due to the fact that the stock must be nominated by at least twice the diameter of the pipe;
- high wear shutter in an intermediate position.
to the pipe valves joined by means of flanges.Most of the parts - cast iron.The gasket material - Asbestos, gland packing - asbestos.
pipelines transporting fuel gas with temperature control up to 100 ° C, using double-disk wedge gate valves, cast iron.They have a non-rising spindle and the working pressure of 0.6 MPa.Only provides for manual control.
Similar double disc gate, but with rising stem placed on a coke oven gas pipelines.They are designed to work at a pressure of 1.8 MPa and a temperature of 200 ° C.
on oil pipelines and oil lines are installed welded steel gate valves.In their design uses a sliding spindle and pipes.The maximum temperature of the medium for these valves is 250 ° C.The material of all the parts is carbon steel valves.
Aggressive media
Locking devices that operate in a hostile environment, selected depending on the characteristics of the medium.It is taken into account period of operation, integrity, reliability, and other parameters that have armature.What is it - shut-off equipment for corrosive environments?
valves are used in corrosive environments often.Such products and valve seat securely mate, to avoid friction.Replaced nodes seals came bellows assemblies.The disadvantage of this hydraulic valve is increased friction.
fluids used in the coupling of brass valves, designed for working pressure of 1.6 MPa.This valve is attached to the pipe by means of a threaded coupling.
in the steam under a pressure of 1 MPa and temperatures below 50 ° C in the valves used brass sealing ring.This ring is made on the spool rubber or leather.
Bellows valves made of steel resistant to corrosion, are used at temperatures up to 350 ° C.Flanged valves have a porcelain body made of porcelain.
Repair
Faults pipeline valves are fraught with many problems for the operating companies.Often, they are not able to block the part of the network which has undergone an accident.It is no accident repair valves, made in time, it helps the company avoid large expenditures in the future.
Causes damage
learn about the most common causes of damage valves.Among the causes of failure of valves include debris falling into the pipeline installation.He settles on the O-ring groove cuts there, breaking the seal.To prevent this, you can thoroughly rinsing backbones prior to their use.Faulty valves repaired in special workshops, which are equipped with lapping machines.They remove the damaged layer of sealing rings, returning them to the old properties.
after making repairs and bolts, before this installation of valves, valve passes hydraulic pressure test bench.If the tests are successful, there is a registration certificate of acceptance.
Manufacturers
In Russia, locking and locking and adjustable fittings are manufactured by many companies.Branch is constantly growing.One of the industry leaders is a plant of valves Also from Chelyabinsk.Popular products of the plant are also Lenpromarmatura from St. Petersburg, Voronezh Hydrogas Company, Ltd. Murom plant of pipeline valves.
Prices
Valves, the price of which can range from 20 to several tens of thousands of rubles, depending on the diameter, material and purpose products are widely offered on the market in Russia and Europe.
