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Ultimate Guide to Dual Plate Check Valve

What is a Dual Plate check valve

The Dual Plate check valve, also known as the butterfly check valve, is a special type of valve used in piping systems. The design structure of this valve consists of two hemispherical or semi-circular discs, which are usually connected by a shaft. The disc opens and closes with the direction of the fluid to prevent the fluid from returning when flowing in the opposite direction.

Dual Plate check valve



Dual Plate check valve structure

The structure of the Dual Plate check valve consists of two semi-spherical or semi-circular valves, which are connected through the shaft to form a structure similar to the wings of a butterfly, so it is also known as the butterfly valve. The motion of the valve disc is related to the direction of the fluid. When the fluid is flowing forward, the valve disc opens to allow the fluid to pass through. In reverse flow, the disc is quickly closed to prevent reverse flow.


The main function of Dual Plate check valve

Prevent reverse flow: When fluid flows in the pipe, the valve allows the fluid to flow in one direction, but prevents the reverse flow. This helps prevent the media in the system from countercurrent, ensuring a steady flow of fluid in the specified direction.

Protective equipment: In some systems, backflow can cause damage to pipes or related equipment. Dual Plate check valves are installed to protect the piping system and connecting equipment from countercurrent effects.

Pressure maintenance: The double-disc check valve effectively maintains pressure in the system while closed. This plays an important role in maintaining stable operation of the system and preventing pressure fluctuations.

Reduce the risk of water hammer: Water hammer is a pressure fluctuation caused by the rapid stop or change of flow direction of the liquid. The use of double-disc check valves helps to slow the speed of the fluid and reduce the risk of water hammer.

Energy savings: Preventing backflow prevents unnecessary energy loss in the system. This is beneficial for improving the efficiency of the system and saving energy.


Parts of Dual Plate check valve

Cast Steel WCB 10” 150LB RF Flange Dual Plate Check Valve

Cast Steel WCB 10” 150LB RF Flange Dual Plate Check Valve

Valve Body: The valve body is the main housing of the Dual Plate check valve, usually made of metal. The valve body contains a seat, channel, and connection port to ensure that fluid can flow through and be closed when required.

Disc: Dual Plate check valves have two discs or discs, usually located inside the body. The two flaps are designed to open when the fluid is flowing normally and close when it is flowing in the opposite direction, preventing reverse flow.

Seat: The seat is the part of the disc or gate that is touched when it is closed, usually made of a wear-resistant material to ensure good sealing performance.

Spring: Some Dual Plate check valves may be equipped with springs to assist disc or gate closing and provide additional sealing force.

Bearings: Valves or RAMS are usually connected to the body through bearings to ensure that they move smoothly when opened and closed.

Flanges: Double-disc check valves usually have flanged connections for easy installation in piping systems.


Advantages and disadvantages of Dual Plate check valve



Effective anti-reverse flow: The double-disc check valve design allows it to effectively prevent the media in the pipe counterflow, ensuring that the fluid flows in only one direction.

Low fluid resistance: The double-disc check valve causes relatively little fluid resistance when opened, helping to maintain efficient operation of the piping system.

Fast closing: When the medium flows in reverse, the double-disc check valve can be quickly closed to prevent counterflow and maintain the stability of the system.

Suitable for a variety of media: The Dual Plate check valve is suitable for pipeline systems with a variety of media such as liquid, gas and steam.

Simple construction: Double-disc check valves usually have a relatively simple construction and are easy to install and maintain.


Water hammer risk: In some cases, when the Dual Plate check valve is closed, it may cause the water hammer effect, that is, the fluid stops rapidly or changes the direction of flow, which may produce pressure fluctuations.

Limited flow: In the fully open state, the relatively small passage of the double-disc check valve may limit the maximum flux of the fluid, which can be a limiting factor in some applications with high flow requirements.

High opening pressure required: In order for the Dual Plate check valve to fully open, a certain fluid pressure is usually required, which can cause problems in low pressure systems.

Relatively large volume: Dual Plate check valves may have a large volume relative to some other types of check valves, which may need to be considered in cases where space is limited.


Dual Plate check valves are similar to butterfly valves in appearance. How to distinguish between Dual Plate check valves and butterfly valves

butterfly valves



 Functions and applications:

Dual Plate check valve: mainly used to prevent the flow of fluid in the pipeline reverse or backflow. It allows the fluid to flow freely in one direction, but closes the valve when the flow is reversed, preventing the medium from countercurrent.

Butterfly valve: mainly used to control the flow of fluid. The butterfly valve can adjust the flux of the fluid by rotating the disc (butterfly plate), which can be fully opened or closed, or the flow can be controlled by adjusting the Angle of the butterfly plate.

Structure and design:

Dual Plate check valves: Usually have two discs or RAMS designed to open in the direction of fluid flow and close when the flow is reversed. It can adopt a ball, disc or other shaped disc.

Butterfly valve: consists of a rotating disc (butterfly plate), which is fixed on the valve stem. The rotation of the plate can change the diameter of the channel, thereby regulating the area through which the fluid flows.

Fluid resistance:

Dual Plate check valves: Because of their design, Dual Plate check valves cause less resistance when fluid passes through. Suitable for applications where minimal resistance is required.

Butterfly valves: Butterfly valves cause relatively little resistance, especially when partially opened. Therefore, it may not be preferred in some systems with high resistance requirements.

Installation and maintenance:

Dual Plate check valves: Usually vertically mounted, suitable for horizontal and vertical pipes. Installation is relatively simple.

Butterfly valve: Usually horizontal installation, need sufficient space. Due to the nature of its rotating parts, more maintenance may be required.

Application of Dual Plate check valve

Water treatment systems: In water supply and drainage systems, Dual Plate check valves are used to prevent the flow of water from reversing, ensuring that the water flows in only one direction and preventing the water from being contaminated.

Chemical industry: In chemical processes, double-disc check valves can be used to prevent chemical backflow and protect equipment and piping systems from unnecessary damage.

• Oil and gas industry: In oil and gas pipeline systems, double-lobe check valves prevent oil and gas backflow, ensuring that fluid flows in the specified direction while reducing pressure fluctuations in the pipeline system.

Power plants: In power generation equipment and circulating water systems, double-disc check valves are used to prevent cooling water from reversing and maintain stable operation of the system.

Pharmaceutical industry: In pharmaceutical production, double-flap check valves help to avoid cross-contamination of medicines and materials and ensure the correct direction of fluid flow.

Food and beverage industry: In food processing and beverage production, double-disc check valves are used to prevent impurities from entering the product flow and ensure product quality.

Heating, ventilation and air conditioning systems: In HVAC systems, Dual Plate check valves are used to prevent hot or cold water from backstreaming and maintain the efficiency of the system.

Fire protection systems: In fire protection water sources and sprinkler systems, Dual Plate check valves ensure that water flows in only one direction, preventing backflow of the piping system.


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