Flanged horizontal check valve. Check valve (flanged, wafer)

In a lift check valve, the shut-off element is a lift spool. Under the action of water pressure, the spool rises, allowing the flow to pass. When the pressure drops, the spool is lowered onto the seat, preventing flow back. Such valves are installed only in horizontal pipelines. Required condition- vertical arrangement of the valve axis.

The valves are divided into four groups according to the method of attachment:

• Welded attachment: The non-return valve is welded to the pipeline. It is used when working in aggressive environments.
• Flange mounting: The check valve is connected to the pipeline through gasket flanges.
• Coupling fastening: the valve is fastened to the pipeline through a threaded coupling. Used in systems not large diameter.
• Wafer fastening: the check valve does not have its own fastener. Clamped between pipeline flanges. It is used in areas with limited dimensions.

Lift check valves with a safety net at the inlet and designed to be installed at the beginning of the suction line are called foot valves.

Advantages of lift check valves:

• simplicity of design;
• reliable tightness;
• the possibility of repair without dismantling the entire valve.

Disadvantages of lift check valves:

• high hydraulic resistance;
• the possibility of jamming the shutter in the guide part of the cover when using the valve in systems with a contaminated working environment;

Ball check valves

In a ball check valve, a ball element serves as a gate. A spring is used as a clamping element, pressing the ball against the seat. These valves are usually made for small pipe diameters and are used as domestic plumbing equipment. The ball check valve is inferior to the spring disc valve in dimensions.

Swing check valves, operating principle:

In this design, the shut-off element is a slam-shut valve. The flapper pivot axis is above the through hole. Under the action of the “slam” pressure, it leans back and does not interfere with the passage of water. When the pressure drops below the permissible value, the spool falls and closes the bore. In large diameter check valves, swipe the spool against the seat, which leads to a rapid failure of the structure. With further operation, this provokes the occurrence of a water hammer when the check valve is triggered. Therefore, rotary check valves are divided into two groups: Simple - valves with a diameter of up to 400 mm. They are used in systems where shock phenomena cannot seriously affect the operation of the hydraulic system and the valve itself. Bumpless - valves with devices that ensure a smooth and soft fit of the spool on the seat. The advantage of rotary valves is the ability to handle large systems and low sensitivity to environmental contamination.

A non-return valve is a protective valve that is installed on the pipeline. The main task of the part is to prevent the return flow of the substance in the event that the pump turns off or fails, the pipeline breaks. Simply put, a valve is a safety device that activates automatically.

What is the special feature of a check valve?

An element such as a check valve protects pipelines, equipment and the pumps themselves during an emergency. At the same time, the valve is used to combine the operation of several pumps in one line. The main task of the valve in this case is to protect the devices from excessive pressure.

The mechanism of action of the device is simple. If there is no flow of the working medium, the flapper is in the closed position under the influence of its own weight. If the working medium moves through the pipeline, then the seat opens under its weight. But as soon as the substance changes its direction, the clap returns to its original position.

All check valves fall into two categories:

• check valves - made of steel and cast iron. The main areas of application are water supply and heating systems, water distribution and pumping stations... There are rotary, lifting, spring, coupling and reverse;
• check valves - the valve is made in the form of a disc.

Return products are most often mounted on horizontal pipelines.

Five advantages of safety valves:

• simplicity of structure - makes it possible to easily and quickly service and repair parts;
• small stroke - only 0.25 DN is required to completely block the passage;
• compact dimensions and low weight;
• additional regulatory functions;
• the possibility of the pipeline functioning at high working pressures and at substantial pressure drops.

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

Pipeline 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-type products designed for industrial and domestic use and designed for a long service life.

The advantages of check valves are:

• automatic actuation without additional power consumption;
• reliability;
• performance of functions both in normal and emergency operating conditions;
• lack of significant impact on throughput pipeline.
• opening the shutter at minimum pressure 0.5 bar (gravity).
  

You can buy check valves for household and process water supply systems, heating, steam systems, oil and chemical industries, sewage systems at reasonable prices. The products can be used in pipelines for the transportation of non-aggressive liquids and gases.

The catalog contains check valves with threaded, flanged and wafer-type fastening in cast iron, carbon and stainless steel, brass, bronze bodies. 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 closed. Under the influence of a moving working medium, the shutter automatically opens and closes when it stops. The spool opens in only one direction, therefore no backflow of the medium is possible.

Types of check valves

We offer ball and globe check valves with different kinds fastening.

Conventional feed-through models are for horizontal mounting only. Ball check valves can be installed horizontally and vertically, since they use a ball element as a shutter. These types of fittings are available with threaded and flange fastenings.

Wafer check valves are installed in flanged bursts of pipes. They can be mounted vertically or horizontally. A flat disc is used as a shutter. Double-leaf valve designs are equipped with damping elements to successfully resist water hammer.

Flanged check valve - a kind of protective pipeline fittings... It differs from other modifications by the type of connection (flange). Refers to the types of direct-acting valves with automatic control - passes the flow of the working medium in one direction. When the direction is reversed, the valve automatically closes the flow area. The force is used for this from the gravity of the shutter, from the spring, from the lever-load mechanism.

Using flanged valves

Placement of check valves prevents abnormal situations in piping systems in the event of an emergency drop in pressure. Flanged check valves are installed on the pressure head sections of pipelines (according to the number of pumps connected in parallel), on pipelines after the meter (flow meter), in complex heating systems, water supply, and other working medium in areas requiring movement only in one direction (make-up valves closed systems; valves in front of the cleaning filters).

Advantages

The flange design slightly increases the connection size. This feature is compensated by the ease of installation, maintainability of the valve, unpretentious operation (not required Maintenance). In addition, flanged check valves are reliable in operation, provide complete shutoff of the reverse flow of the working medium. It is possible to select a full bore valve design with a minimum of hydrodynamic losses.

Design features

Flanged valves have a cast metal (usually cast iron) body. Mounting flanges are provided on both sides. The internal design is determined by the type of bolt used. The most common types of mechanisms are: lifting, ball, disk, rotary.

Installation of flanged valves

All types of flanged check valves are installed in the pipeline taking into account the direction of the forward flow. In valves with a breechblock mechanism, the normal closed position of the breech is maintained by a spring. When the flow moves under the valve, the valve opens. Such a valve is mounted on vertical, inclined, horizontal sections.

In ball valves, a shut-off element in the form of a metal ball is used. In the absence of flow or in the opposite direction, the ball, under its own weight, closes the passage hole. Installation of such flanged valve carried out in compliance with the orientation of the ball chamber up.