Flanged check valves. Flanged check valve: application, types, advantages and disadvantages Plumbing flange check valve

In the lift check valve, the shut-off element is the lift spool. Under the action of water pressure, the spool rises, passing the flow. When the pressure drops, the spool drops onto the seat, preventing the flow from flowing back. Such valves are installed only on horizontal sections of pipelines. A prerequisite is the vertical position of the valve axis.

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

• Butt Weld Attachment: The check 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 sealed flanges.
• Coupling: The valve is attached to the pipeline through a threaded coupling. It is applied in systems of small diameter.
• Wafer fastening: the check valve does not have its own fastening unit. Clamped between pipeline flanges. It is applied on sites with restriction on dimensions.

Lift check valves with a protective mesh at the inlet and intended to be installed at the beginning of the suction pipeline are called foot valves.

Advantages of check valves:

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

Disadvantages of 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 shutter. A spring is used as a clamping element, pressing the ball to the seat. Such valves are usually made for small diameter pipelines and are used as domestic plumbing fixtures. The check ball valve loses to the spring disc valve in dimensions.

Check valves, principle of operation:

In this design, the locking element is a spool - "slam". The axis of rotation of the "flap" is above the through hole. Under the action of pressure, the "clap" leans back and does not prevent the passage of water. When the pressure drops below the permissible value, the spool falls and slams the through passage. In check valves of large diameter, the spool hits the seat hard, which leads to a quick failure of the structure. During further operation, this provokes the occurrence of water hammer when the check valve is activated. 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 impact phenomena cannot seriously affect the operation of the hydraulic system and the valve itself. Impactless - valves with devices that ensure a smooth and soft landing of the spool on the seat. The advantage of rotary valves is the ability to operate in large systems and low sensitivity to environmental contamination.

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

Using Flanged Valves

The placement of check valves prevents the occurrence of emergency situations in pipeline systems during an emergency pressure drop. Flanged check valves are installed on pressure sections of pipelines (according to the number of pumps connected in parallel), on pipelines after a counter (flow meter), in complex heating systems, water supply, other working media in areas that require movement in only one direction (make-up valves of closed systems; valves in front of the cleaning filters).

Advantages

The flange design slightly increases the size of the connecting dimension. This feature is compensated by ease of installation, maintainability of the valve, unpretentiousness in operation (maintenance is not required). In addition, flanged check valves are reliable in operation and provide complete shut-off of the return flow of the working medium. It is possible to choose a full-bore valve design with a minimum of hydrodynamic losses.

Design features

Flanged valves have a cast metal (more often cast iron) body. Mounting flanges are provided on both sides. The internal design is determined by the type of bolt mechanism used. The most common types of mechanisms: 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 direct flow. In lift-gate valves, the normally closed position of the gate is maintained by a spring. When the flow moves under the shutter, the valve opens. Mount such a valve on vertical, inclined, horizontal sections.

In ball valves, a locking 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 through hole. The installation of such a flanged valve is carried out with the orientation of the ball chamber upwards.

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 applications and designed for a long service life.

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 a body made of cast iron, carbon and 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 of the medium is possible.

Types of check valves

We offer ball and straight check valves with various mounting options.

Conventional feed-through models are designed for horizontal mounting only. Ball check valves can be installed in a horizontal and vertical position, since 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.

Flanged check valve Granlok RD30 is designed to protect pipelines from the reverse flow of the working medium. It is intended for the pipelines transporting technical hot, cold water, steam, neutral environments.

Installation

The rotary check valve can be installed both in horizontal and vertical position. Installation to the pipeline is carried out using flanges. The direction of medium flow must match the direction indicated on the valve. The valve is installed on a horizontal pipeline so that the axis of the disc is higher than the axis of the pipeline and is located in a horizontal plane. On a vertical pipeline, valves are installed with the inlet pipe down so that the axis of the disk is in a horizontal plane

Specifications

Flange connection according to DIN 2501 (DIN 2633 at PN 1.6 MPa) / EN1092-2.

It is possible to use Russian-made counter flanges in accordance with GOST 12820-80, 12821-80 for PN 1.6 MPa.

Specification

Overall dimensions and parameters

The check valve is a protective fitting that is installed on the pipeline. The main task of the part is to prevent the reverse flow of the substance in the event that the pump is turned off or fails, the pipeline breaks. Simply put, the valve is a fuse that activates automatically.

What is the feature of the 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 activities of several pumps into one line. The main task of the valve in this case is to protect the devices from excessive pressure.

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

All check valves fall into two categories:

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

Return products are most often mounted on horizontal sections of pipelines.

Five advantages of safety valves:

• simplicity of structure - makes it possible to easily and quickly maintain and repair parts;
• small stroke - to completely block the passage, only 0.25 Dy is required;
• compact dimensions and low weight;
• additional regulatory functions;
• possibility of operation of the pipeline at high operating pressures and with solid pressure drops.