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Shut-off valves

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Ball valve Yoshitake BLV1 Ball valve Yoshitake BLV-1
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  • Manufacturer: Yoshitake (Japan)
  • Max operating pressure: saturated steam: 1.0 MPa; water, oil, air, other non-hazardous media with temperatures up to 40 ° C: 4.12 MPa
Shutoff valve Yoshitake GLV1 Shut-off valve Yoshitake GLV-1
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  • Manufacturer: Yoshitake (Japan)
  • Material: Bronze, bronze or brass
Shutoff valve Yoshitake GLV16 Shut-off valve Yoshitake GLV-16
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  • Manufacturer: Yoshitake (Japan)
  • Material: Ductile iron, stainless steel
Bvalve BV25061 check valve Bvalve BV25061 check valve
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Price: specify
  • Manufacturer: Bvalve (Spain)
  • Operating pressure: 16 bar
  • Compound: DN15–DN250
  • Max working temperature: 300 (°C)
  • Material: Cast iron, EN-JL 1040
Bvalve BV25066HP Gate Valve Bvalve BV25066HP Gate Valve
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  • Manufacturer: Bvalve (Spain)
  • Operating pressure: 40 bar
  • Compound: DN15–DN300
  • Max working temperature: 400 (°C)
  • Material: Stainless steel CF8M
Bvalve BV25066 check valve Bvalve BV25066 check valve
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Price: specify
  • Manufacturer: Bvalve (Spain)
  • Operating pressure: 40 bar
  • Compound: DN15–DN300
  • Max working temperature: 400 (°C)
  • Material: Stainless steel CF8M
Bvalve BV25065HP Gate Valve Bvalve BV25065HP Gate Valve
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Price: specify
  • Manufacturer: Bvalve (Spain)
  • Operating pressure: 40 bar
  • Compound: DN15–DN300
  • Max working temperature: 400 (°C)
  • Material: Cast steel 1.0619
Bvalve BV25065 check valve Bvalve BV25065 check valve
in stock
Price: specify
  • Manufacturer: Bvalve (Spain)
  • Operating pressure: 40 bar
  • Compound: DN15–DN300
  • Max working temperature: 400 (°C)
  • Material: Cast steel 1.0619

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General information about what the shut-off valve is intended for

Is it possible to imagine any closed (pipeline) system with any type of working medium (liquid, steam or gas), without shut-off and control valves? Even at the household level, any man in the street knows: in order to start or stop supplying the medium through pipes to consumers, you must first find and open (or close) the "tap". A more technically savvy person will confidently assert that you need to look not for a "tap", but for a "valve". Well, the experts know: what in the old-fashioned way is called “taps” or “valves” by the common people, for a long time, at least since 1982, among professionals it is customary to call shut-off or shut-off-control valves.

A shut-off valve is a type of pipeline shut-off and control valves designed to shut off and (or) regulate the flow of the medium, in which the shut-off element (in the form of a conical valve, poppet valve) moves parallel to its flow. Its main design features are:

  • reliable operation of the shut-off unit in various operating modes;
  • the ability to ensure high tightness of locking.

This makes it possible to use shut-off valves (valves) under the most severe operating conditions: by operating temperature - up to 600 degrees C, by operating pressure - up to 250 MPa.

Due to the peculiarities of their design, shut-off valves (valve type) can be used on pipelines with a bore of up to a maximum of 300 mm (DN300), being an intermediate link between pipeline valves (used on large pipelines) and pipeline valves (usually used on pipelines up to 2 ½ inches (63mm) through diameter). By their basic design, gate-type shut-off valves are:

  • Straight passages - in them, the inlet and outlet flows are oriented in the same direction, but they are not located along the same axis, but parallel to each other. Thus, in the body of the globe valve, the flow of the medium is forced to make as many as two turns of 90 degrees. Such a fundamental design is characterized by the simplicity of the locking mechanism implementation, versatility of application, but at the same time - by the highest hydraulic resistance.
  • Angular - in them the inlet and outlet flows are mutually oriented at an angle of 90 degrees. While maintaining the simplicity of the locking mechanism implementation, this design option has a limitation in application - only for places where the pipeline changes its direction.
  • Direct-flow - in them, the flow of the medium is made more or less straight, practically along the axis of the pipeline (to minimize hydraulic resistance). But in such a design, the locking mechanism is forced to orient itself at an angle to the direction of flow, which complicates its implementation and design.

Запорные клапаны

Device, operation diagram of the shut-off valve

Structurally, the shut-off valve (valve) is made on the basis of a straight-through body, which has two nozzles - inlet and outlet. Valve branch pipes are made with flange or coupling (threaded) fastening required for connection to the pipeline. Inside the body, where the through passage can be rotated by 90 degrees, it is equipped with a seat for a locking gate (spool). The valve plug is driven by a rotary stem which forms a threaded pair together with a travel nut. Travel nut:

  • or is located in a removable cover of a shut-off valve (in this case, the thread of the running pair of the spindle and nut is under the influence of the working environment, which often adversely affects its corrosion resistance and performance);
  • or it is carried out into an external yoke assembly (in this version, the corrosive effect of the working medium on the running thread is excluded, it is very easy and simple to maintain (lubricate)).

The rotating stem of the valve passes through the valve bonnet (where it is sealed with a gland seal or bellows) and is driven by a steering wheel (valve).

The spindle of the shutter, turning manually with the help of the control wheel, is set in rotary-translational motion in a threaded pair with a running nut. When screwing in the rotary spindle, it lowers the shutter (spool) into the seat, which thus blocks the flow of the medium. When unscrewing the spindle, on the contrary, it raises the valve above the seat, slightly opening the flow area of the internal channel of the valve.

The bellows seal of the valve stem (bellows) is used instead of stuffing box type seals in situations where it is necessary to ensure the tightness and operability of the mechanism in conditions of high operating temperatures, pressures, when working with aggressive media. The bellows is a corrugated metal tube capable of changing its longitudinal size due to its crushing. Attached as a seal to the spindle, it accompanies its translational movement by its own compression or expansion, thereby ensuring a very high tightness of the seal.

Запорные клапана ОПЭКС

Regardless of the rotary-translational drive through the threaded pair, which provides for the possibility of intermediate (partially opening the flow) positions of the shutter (spool), the shut-off valve (valve) is designed to operate only in the modes of full locking (“fully closed”) and full unlocking (“fully open"). For operation in partial modes of locking and unlocking, special variants of shut-off and control valve valves are designed. In addition, there are designs of stop valves not with a rotary spindle (valve type), but with a smooth stem, to which the translational movement is given by a spring-lever, electromechanical drive, etc.

Ходовая гайка вынесена на внешний бугельный узел.

Fig. 1 Option of a straight-through shut-off valve. The running nut is placed on the outer yoke assembly.

Вариант реализации углового запорного клапана.

Fig. 2 A variant of the implementation of the angle shut-off valve.

Вариант запорного клапана с сильфонным уплотнением (сильфоном)

Fig. 3 Bellows Seal (Bellows) Stop Valve Option

Advantages and disadvantages of a check valve

The undeniable advantages of a shut-off valve are:

  1. The ability to provide high tightness of closing, which is not attainable in the design of pipeline valves. This makes it possible to use them in systems with a very wide range of operating pressures, from vacuum to 250 MPa (dampers - up to a maximum of 50 MPa). The possibility of using a bellows seal in the design of the shut-off valve makes it possible to ensure high tightness not only in the shut-off unit, but also of the entire mechanism (fitting) as a whole.
  2. The design of the valve-type locking unit is insensitive to changes in the geometric dimensions of parts under the influence of temperature fluctuations (especially for the valve / seat assemblies of a conical rather than a spool shape). Its use is possible both on cryogenic equipment and at high ambient temperatures, up to 600 degrees C inclusive.
  3. The flow is shut off virtually frictionlessly in the shut-off unit (plug / seat), which leads to its long service life, significantly exceeding that of pipeline valves and valves.
  4. The absence of friction in the locking unit leads to the presence of a relatively low control force, and therefore valve valves can be used on pipelines of much larger bore section than ball valves.

But it is also worth highlighting the disadvantages of shut-off valves:

  1. Relatively high hydraulic resistance even in a fully open state, which requires taking into account and correcting (increasing) the working pressure in the system. For this reason, valve valves are not suitable for main pipelines, they are mainly used at subscriber inputs for consumers, at water intakes of local water supply systems, in their separate supply or circulation circuits.
  2. The valve design allows the flow of the medium in only one direction (usually indicated by an arrow on the body of the fitting).
  3. Since the locking element (gate, spool) moves parallel to the flow of the medium, overcoming its resistance, then with an increase in the flow area of the pipeline and the pressure (speed) of the medium, the required control force also increases. With an increase in the bore diameter of the pipeline, it becomes more difficult to ensure a high-quality fit of the valve on the seat. The combination of these factors limits the scope of application of gate valves to pipelines with bore diameters up to DN250 - DN300.

Check valve selection

The selection of a gate valve type is carried out according to the following parameters of the pipeline system:

  • under the bore diameter of the pipeline section where the fitting is planned to be installed;
  • the nature of the connection to the pipeline - flanged or threaded (coupling);
  • by the nature of the working environment: gas, liquid, chemically aggressive;
  • by operating and maximum allowable pressure in the system, including for the conditions of evacuation;
  • according to the maximum permissible temperature of the working environment, including for cryogenic conditions.

Bvalve shut-off valves with bellows seal for steam, superheated water

OPEKS Energosystems, which specializes in the production of high-quality heat exchange and other heat-and-power equipment, recommends its customers to use exclusively high-quality pipeline valves and valves to ensure its efficient regular operation. And as such, I am ready to offer in its assortment the products of one of its commercial partners - the well-known European (Spanish) company BVALVE Flow, Systems & Controls.

Запорные клапаны Bvalve с сильфонным уплотнением

Our assortment includes a number of models of very high quality and reliable shut-off valves (valve type) with a multilayer bellows seal TM Bvalve, suitable for a wide range of pipeline bore diameters, operating temperatures and media pressures, mainly with a flanged system of attachment to the pipeline. All Bvalve check valves in our range are designed with a highly reliable and easy-to-maintain yoke assembly, and the bellows is of a multilayer design that provides over 10,000 opening and closing cycles. Among them, the consumer will be able to find:

  • valve models, both for the smallest (DN15) and the largest (DN300) bore diameters available for this type of shut-off pipeline valves;
  • shut-off valves with hermetic bellows seals, for operation with superheated water and steam, at operating pressures up to and more than 63 bar;
  • shut-off valves for working with a wide variety of media (water, oil products, compressed air and steam, corrosive liquids and gases) made of carbon, stainless steel, various grades of corrosion-resistant cast iron.
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Shutoff valves

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