The check valve is vertical flanged. Flanged check valve. Using Flanged Valves

The PASADOR company offers to buy check valves of various modifications at attractive prices. We supply products to all regions of Russia.

Pipe fittings of this type are used to prevent the reverse movement of the working medium (water hammer or back pressure). Our range includes threaded, flanged and wafer products designed for industrial and domestic use and designed for long term services.

The advantages of check valves are:

• automatic operation without additional energy consumption;
• reliability;
• performance of functions both in normal and emergency operating conditions;
• no significant impact on the throughput of the pipeline.
• valve opening at a minimum pressure of 0.5 bar (gravity).
  

You can buy check valves from us for domestic and process water supply systems, heating, steam systems, oil and chemical industries, sewerage at affordable prices. Products can be used in pipelines for transportation of non-corrosive liquids and gases.

The catalog contains check valves with threaded, flanged and wafer mounting in cast iron, carbon and of stainless steel, brass, bronze. Most models are designed for horizontal and vertical installation.

The design consists of a body and a shutter, the mechanism of which is a spool. In the absence of flow, this type of valve is in the closed state. Under the influence of a moving working medium, the shutter automatically opens and closes when it stops. The spool only opens in one direction, so no reverse flow is possible.

Types of check valves

We offer ball and straight check valves with various types mounts.

Conventional walk-through models are only for horizontal mounting. Ball check valves can be installed in a horizontal and vertical position, as they use a ball element as a shutter. These types of fittings are available with threaded and flange mounting.

Wafer type check valves are installed in flanged pipe breaks. They can be mounted in vertical and horizontal position. A flat disk is used as a shutter. Designs with double-leaf gates are equipped with damping elements to successfully resist water hammer.

The main task that the flanged check valve, installed on pipelines, solves for various purposes, is to ensure the movement of the transported medium in one direction. Design features check valve, for installation of which a flange is used, allow such a device to automatically stop the movement of the transported medium at the moment when such movement begins to be carried out in the wrong direction. Check valves of flange type are installed mainly on pipelines through which liquid media are pumped.

Features and applications of check valves

Check valves various types(including flanged ones) are used to protect the pipeline from:

• the occurrence of reverse flows of the working environment in it;
• hydraulic shocks.

The reverse flow in pipelines, as is clear from its name, is the movement of the working medium in the opposite direction. This can happen, in particular, when the pump that provides the supply of the working medium and its movement is switched off. If for heating systems such a phenomenon as reverse flow is not particularly critical, then it cannot be allowed to occur in sewer and water systems, as well as in pipelines through which oil products and other media are transported. That is why the use of check valves in such pipeline systems is a mandatory requirement.

Another undesirable phenomenon, from the consequences of which pipeline systems are able to protect a flanged, wafer-type check or any other valve, is water hammer. It is characterized by the fact that a sharp pressure drop of the transported medium occurs in the pipeline, which leads to the formation of a shock wave passing along the entire length of the pipeline system.

Water hammer can eventually lead to the destruction of individual sections of the pipeline and the failure of the elements that are used to ensure its normal operation. With the help of check valves installed by means of flanges or in any other way, the system is divided into separate isolated sectors, which makes it possible to effectively protect it from the effects of water hammer.

Operating principle

The principle by which check valves work is quite simple, meanwhile, such devices are very effective and are able to provide reliable protection parts of pipeline systems. Any check valve, regardless of the type, is made up of a body (steel or cast iron) and a locking element located in it. The locking mechanism works due to the pressure of a special spring, the rigidity of which can be adjusted.

The spring, which is equipped with non-return valves, ensures the opening of their locking elements only in one direction - in the direction of the correct movement of the transported medium. By exerting pressure on the locking element held by such a spring, the liquid or gas pumped through the pipeline opens it and begins to move in the required direction. As soon as the pressure of the working medium in the opening direction of the valve begins to fall, the locking element closes, preventing the liquid or gas from moving in the opposite direction.

Types and properties

The design of the shut-off elements of check valves, for the installation of which flanges are used, may be different. The choice of a flanged valve with a certain type of locking element depends on the tasks for which such a device is intended.

So, depending on the design of the locking element, there are:

• rotary valve;
• lift type check valve;
• non-return valve with ball locking element;
• double-leaf check valve;
• receiving check valve equipped with a grid.

The rotary check valve is a locking device, the main part of which is a steel slamming disk fixed on a spring-loaded axle. At the moment when such a check valve is open, the disk in its inner part is parallel to the movement of the working medium, and when it is closed, it is perpendicular. Flanged swing check valve has a simple structure and, accordingly, low cost. If we talk about the disadvantages of check valves of this type, then the most significant of them is that they rotary mechanism at the moment of closing, the locking disc slams too hard, which eventually leads to wear of the seat. Rotary check valves, equipped with a special mechanism that ensures smooth closing of the locking disc, are deprived of such a disadvantage. However, these improved flanged rotary valves are more expensive, which somewhat limits their application.

In flange-type lifting check valves, a special spool is used as a shut-off element, which, under the pressure of the working flow, rises along the vertical axis, and when the pressure decreases, it falls to its seat, blocking the movement of the medium transported through the pipeline. It should be borne in mind that due to the peculiarities of their design, such valves can only be installed in a vertical position.

Ball check valves, as their name implies, use a spool made in the form of a ball as a shut-off element. Their large size does not allow them to be used as wafer locking devices.

The double-leaf check valve, which is produced mainly in a wafer design, involves the use of two slamming flaps in its design at the same time. Each of them is connected to a spring, which regulates the force of their resistance to the pressure of the working flow. Wafer type butterfly valve due to small sizes its locking elements - sashes - are very compact in size.

Check valves, the design of which is additionally equipped with a strainer, are used for installation on pipeline systems for pumping oil, gas or water from underground sources. Such devices, the most popular model of which is 16Ch42R, simultaneously solve two important problems: their locking mechanism prevents liquid or gas from returning back to the source, and the mesh protects the pipeline from large debris entering it.

Model 16Ch42R, whose body is made of steel or cast iron, is highly versatile and can be installed on pipelines or pumps used for pumping both liquid and gaseous media.

Flanged vs Wafer Check Valves: Differences

Check valves that use flanges for installation in piping systems can be one of the following types:

• flanged;
• interflange.

On flange-type devices, the flange on the supply part and the return flange are welded to the valve body and form an integral whole with it. Flanged check valves are mainly used for fitting pipes large diameter, with the help of which the transportation of working media is carried out on an industrial scale.

There are virtually no fasteners in wafer type check valves. This type of installation, as mentioned above, is very often used for the installation of double-leaf check valves. In this case, the valve itself (in particular, a double-leaf wafer valve) is installed between two flanges fixed at the ends of the connected pipes. After being placed in special seats which are equipped sealing elements, the flanges are pulled together with threaded studs. Despite the apparent unreliability of such a connection, if it is done correctly, the wafer check valve is fixed with the same reliability as any other type of device.

Check valves can be installed on pipeline systems using not only flanges, but also couplings or welded joints. However, if we talk about pipelines of large diameter, such valves are installed on them only using flanges.

Advantages and disadvantages of flange type check valves

Since flange-type check valves are most often used to equip pipelines through which the working medium is transported with high intensity, the internal elements of such devices (in particular, the locking mechanism) experience significant shock loads during operation. In addition, the flange-type check valve, due to its significant dimensions, is itself the cause of water hammer. In the process of closing the valve flaps in the pipeline in which it is installed, the pressure inevitably increases, which leads to the formation of a water hammer.

In those pipeline systems in which water hammer is not able to have a significant impact on performance as individual elements, and the system as a whole, simple type check valves are used. The diameter of the latter, as a rule, does not exceed 400 mm. In other cases, non-impact type check valves are used. Smooth and soft closing of the locking element in flanged shockless type valves can be provided by special weights or hydraulic dampers. Meanwhile, when choosing non-impact type check valves for equipping a pipeline system, it should be borne in mind that they can only be installed in horizontal sections.

Some of the most significant benefits of flanged check valves include:

• compact dimensions, which allows you to install such devices on almost any part of the pipeline system;
• opportunity effective work even in those systems in which the working environment is characterized by severe pollution;
• the possibility of installation on pipelines with a large diameter.

Features of choice

The main parameters that you should pay attention to when choosing a check valve (including a flanged one) are:

• operating pressure at which such a device can operate;
• conditional diameter.

You can find out what operating pressure the check valve corresponds to by marking the device in which given parameter denoted by the letters RU. The numbers in the marking after such letters indicate the working pressure for which the device is intended. For example, the designation RU16 indicates that a flanged valve can operate at a pressure of 16 bar without being subject to excessive wear.

Wafer is the type of device that is connected to the pipeline through a wafer or flange connection. The conditional passage in diameter for it can vary between 15-400 millimeters.

check valve can be swivel or lift. Rotary can be unstressed or simple, and lifting can be horizontal or vertical (depending on the type of pipeline for which it is used). In addition, there are single-seated and multi-seated valves.

The wafer check valve is designed to prevent reverse flows of the internal medium in the pipe, as well as water hammer. He does not represent stop valves. According to the constructive device, it can be rotary, lifting, ball or spring. It is customary to characterize a wafer type check valve by the feature of the penetration of the working medium in only one direction, and a flange connection is used for its fastening. The flange is the connecting part of the pipeline, which is a frame or disk equipped with holes for bolts. The flange is used to join pipelines with fittings, in addition, it can be part of a gate, fitting or pipe. The wafer check valve is intended for mounting on pipelines located horizontally, which prevents the formation of reverse flows in the internal environment. The fittings of this type are regulatory mechanisms. This type may well become a replacement for heterogeneous taps, as well as shut-off taps.

The wafer check valve is intended for installation on technical pipelines, where it automatically protects and blocks the occurrence of reverse flow. It is advisable to use it for a variety of liquids, steam and gas. By design, such valves provide the proper level of tightness, excluding the appearance of this type of valve. Installation of this type of valve is possible in a vertical or horizontal position. During installation, it is clamped between two flanges. The flow of the medium is directed to the valve disk, marked with an arrow.

The professional wafer check valve is applicable for guaranteed reliable sealing of pipelines from the formation of unwanted flow in the opposite direction, which is usually formed from the medium used for various reasons. can be used in many heating systems, as well as in modern chemical, household, food and other industries. Such a valve is able to work in different working environments: chemical mixtures, air, water in hot or cold supply systems, sea water, drinking water, mineral oils, petroleum products and gas, as well as in other types of media.

This type of valves can be made from a fairly wide range of materials, among which the most popular are usually distinguished: cast iron, brass, steel, copper. This allows it to be used as a connecting part of pipelines at different pressures and temperatures, while its functioning remains at a fairly reliable level, regardless of the working environment.

Large pipelines intended for operation in difficult working conditions must be protected from pressure drops and prevent the formation of backflows in them, etc.

If this is not done, the system may crash, which is not so easy to solve. The simplest and most effective tool for such tasks is considered to be wafer or ball.

All of them have differences in design, but one goal is to protect the pipeline from negative impact reverse flows and everything connected with them.

Article content

Features and purpose

As we noted above, the reverse, as well as their varieties, in fact, perform similar, almost identical tasks.

They protect equipment for water supply or heating from:

• reverse flows;
• water hammer.

Let's figure out what this reverse flow is. Reverse flow in pipes is an interesting phenomenon characterized by a change in the direction of flow in pipes.

Imagine, for example, a heating system in a private house. In heating, the heated carrier must move constantly through the pipes so that the water does not stagnate; small circulation pumps are mounted.

The pump, by its work, provokes movement, by forcing pressure in the pipes. If it is turned off, then for a short period a kind of vortex can form inside the pipeline. Confusion with pressures will cause water to flow in the opposite direction.

For heating systems, such things are not particularly scary. But we are not limited to them either. For sewerage, large water supply pipes, industrial systems transportation, etc. the formation of a reverse flow is very undesirable. Therefore, such things are strictly regulated there, and all dangerous places are protected.

The second dangerous factor is water hammer. Water hammer refers to sudden pressure drops in pipes, when a kind of shock wave is formed, passing along its entire length. Bumping into resistance, it has a destructive effect on problem areas. One water hammer is not a problem. Even a dozen will not give a serious negative effect.

The danger here is that water hammer - a periodic phenomenon, over time, they will still provoke destruction or severe wear of pipeline sections, which is desirable to avoid.

A steel check valve prevents such problems. It becomes a kind of bulkhead, airlock doors dividing the system into isolated sectors. Problems that appeared in one sector remain in it.

Operating principle

The non-return steel valve works thanks to a unique and very convenient design. This design is simple, but at the same time extremely effective.

Consider a standard steel sample, without going into the details of its individual varieties.

The basic steel receiving fitting consists of a body and a locking element. The body is made of steel or cast iron, with a certain diameter and properties.

Inside the case is a locking mechanism. The mechanism, it does not matter whether it is ball, double-leaf or lifting, works due to the pressure of a special spring. Spring stiffness can be adjusted.

The spring works in one direction, that is, it allows the shut-off element to open with the correct flow in the pipes.

If the water has set in motion, it begins to put pressure on the shutter or shut-off element of the check valve. The spring will withstand the pressure until it exceeds allowable rate, then the valve will start to open.

A decrease in pressure signals that the flow of water is weakening. The lower the pressure, the more the spring works out. As soon as it falls below a certain mark, the spring will slam shut.

All the water that has managed to pass through the bulkhead will remain in its place and will flow further. The flow cannot reverse, since the shut-off element in the valves opens only in one direction - in the direction of the given flow movement.

Types and properties

Let us draw your attention to the fact that the design of such equipment may differ depending on what tasks it faces, and what specific variety we are considering. is not the same as a wafer type butterfly valve, and both are different from what is a meshed foot valve.

So, by design type steel sample is divided into:

1. Turning.
2. Lifting.
3. Double leaf.
4. Reception, with a grid.

In order to avoid such inconvenience, manufacturers have come up with a rotary steel sample with a soft closing mechanism. It's a pleasure to work with him. The only downside is the cost.

The lifting sample uses a spool as a locking element. Lift valves are mounted exclusively vertically. The spool under the pressure of the flow rises along its vertical axis, and - falls to its original place.

involves the use of a ball valve. Differs in large dimensions, therefore it cannot be used as a wafer unit. Otherwise, this is a standard locking piece.

A bicuspid valve is usually composed of two working flaps. They are both connected to an internal spring that regulates the resistance force of the leaves. The sashes are miniature, take up almost no space, so the products with them are very compact.

A suction valve with a filter mesh is a type of fitting designed exclusively for pumps that extract something from the bowels of the earth. The mesh prevents large debris from getting inside the pipe, and the locking mechanism prevents the pumped out liquid from returning back. A striking example of such equipment is the 16ch42r model.

Model 16ch42r is a check valve for large pumps. Reinforcement 16ch42r is produced mainly from steel or cast iron. The 16ch42r valve is good for its versatility. It effectively shows itself in the extraction of both water and oil and gas.

Connection types

It differs in this type and in the method or place of connection.

Allocate valve:

• flanged;
• interflange;
• welded coupling;
• coupling threaded.

The flange model has flanges welded on the ends of the body. It is specifically designed to solve problems in the industrial field or large-scale civil water supply systems.

The wafer valve is distinguished by the absence of fasteners as such. It looks like a short (up to 10 cm wide) piece of pipe with valves. It does not need to be welded or screwed, it is enough place between flanges, or rather their sealing, and then tighten the flanges with long studs.

Contrary to popular belief, the wafer pattern, provided that it is correctly installed and well fixed, holds up no worse than its counterparts with a more traditional approach.

Coupling models are designed for installation on medium and small pipelines with DU25-D32. Coupling samples with DN50 or more are quite rare. The welded socket element is welded to the pipes, while the threaded element is oriented for installation by screwing the union nuts onto the previously prepared thread.

Check wafer valve and its subspecies (video)

Pressure and conditional pass

In terms of characteristics, when choosing, pay attention to the nominal diameter and pressure.

The working pressure is marked with the abbreviation RU. For example, adding the entry RU16 in the name means that we have a fitting that can withstand a nominal pressure of 16 bar. It is understood that with this level of pressure it works without any costs or excessive wear.

The approximate diameter is denoted by the abbreviation DU. Accordingly, a valve with DN25 in the name will have a nominal diameter of approximately 25 mm, with DN32 - 32 mm, with DN100 - 100 mm, etc.

It depends on the control where we can use the fitting and for what purposes. The remote control of the valve must necessarily correspond to the remote control of its adjacent parts. The non-return valve with DN80 can only be connected to pipes and fittings with DN80 and nothing else.

As a rule, small-sized models such as DU25 - DU50 are used for civil pipelines and are mainly oriented towards, and all that is more is already industrial products.