COVNA Actuator Valves for Marine

The marine valve is a device used to control the pressure, flow and flow direction of the fluid in the ship’s pipeline to meet the environmental conditions of the ship.

The marine valve is a control device for the fluid pipeline. Its basic function is to connect or cut off the flow of the medium in the pipeline, change the flow of the medium, change the flow direction of the medium, adjust the pressure and flow of the medium, and protect the normal operation of the equipment in the pipeline.

Below I will introduce to you the actuator valves of COVNA suitable for marine use.

Knife Gate Valves

 Knife gate valve has the advantages of simple and compact structure, reasonable design, reliable sealing, light and flexible operation, running smooth, small flow resistance and easy installation. It works normally when the temperature is -10 to 425℃. The gate of the knife gate valve has a shearing function, which can scrape off the adhesive on the sealing surface and automatically remove the sundries. The stainless steel gate can prevent seal leakage caused by corrosion.

Available in pneumatic knife gate valve, electric knife gate valve and manual knife gate valve for your different actuation needs.


Butterfly Valves

Butterfly valve has the advantages of lightweight, reliable performance, simple matching and large flow capacity, especially suitable for occasions where the medium is viscous and contains particles and fibers. When the butterfly valve is in the fully open position, the thickness of the butterfly plate is the only resistance when the medium flows through the valve body, so the pressure drop generated by the valve is very small. So it has better flow control characteristics. The butterfly valve has two sealing types such as soft seal types and metal seal types.

At present, the valve is widely used in food, environmental protection, petroleum, papermaking, chemical industry, teaching and scientific research equipment, electric power and other industries.

The butterfly valve could be driven by electric actuator, pneumatic actuator and manual override.


Ball Valves

Ball valve is a common use valve. Widely used for transport, shut-off, change the direction of flow rate and control the flow rate. It could be customized into high-temperature types, high-pressure types, anti-corrosive types and universal types. Suitable for water, steam, oil, fuel, air, and so on. Offering a reliable valve solution for you.

Also available in electric operated type, pneumatic operated type, and manual operated type.

Here is a brief introduction of valves for marine. Any demand for valves, feel free to consult us at for a cost-effective valve solution.


What Is The Difference Between Pneumatic Ball Valves And Pneumatic Butterfly Valves?

According to the valve type, the pneumatic actuator valve could be divided into pneumatic ball valves and pneumatic butterfly valves.

Pneumatic ball valve is a valve that uses a ball with a circular channel as the opening and closing part, and the ball rotates with the valve stem to realize the opening and closing action. The opening and closing part of the ball valve is a sphere with holes, which rotates around the axis perpendicular to the channel, so as to achieve the purpose of opening and closing the channel.

Pneumatic butterfly valve is a quarter valve used to open, close and regulate fluid flow. It has a simple operation. A 90-degree rotation of a valve or actuator completely opens or closes fluid flow.

Working Principle

Pneumatic ball valve has a 90-degree rotation action, just because its opening and closing part is a sphere, it can be opened or closed only by operating a 90-degree rotation, which is the most suitable for switching. But now the V-shaped ball valve can be used to regulate or control the flow.

Pneumatic butterfly valve is a kind of valve that uses a disc-type opening and closing member to reciprocate about 90° to open, close or adjust the flow of the medium. It has a good function of adjusting the flow and is one of the fastest-growing valve varieties.



Pneumatic ball valves always rotate, no matter how much pressure is applied. Once opened, the pressure hardly drops because the hole in the ball allows 100% flow of gas or liquid.

Pneumatic butterfly valves are constructed so that a portion of the valve flap always interferes with the flow of liquid or gas. This means that there is always a pressure drop when using a butterfly valve. This also means that the butterfly valve may be difficult to open



Pneumatic ball valves are more effective at sealing than pneumatic butterfly valves, so ball valves are generally better suited for projects involving gas flow.

Pneumatic butterfly valves are typically less expensive to build and maintain, so they are commonly used in large municipal water and sewer projects. They are also common in projects that control the flow of water in rivers or streams.

Any demand for pneumatic ball valves or pneumatic butterfly valves, feel free to consult us at for a suitable valve solution.



What is COVNA Pneumatic Control Valve?

Pneumatic control valves are mainly used in transportation systems in medical, food, petroleum, natural gas, water treatment, and other industries, and are suitable for controlling gas, steam, liquid, and other media. Compared with other general pneumatic actuator valves, it adds some control components, and the whole is more complicated, so the required debugging process is naturally more complicated.

Today, we will talk to you about the COVNA pneumatic control valve.

It is characterized by simple control, fast response, intrinsic safety, no need to take additional explosion-proof measures and receives control signals from industrial automation control systems to adjust various process parameters such as flow and pressure of pipeline media.

Pneumatic control valve is usually composed of a pneumatic actuator and modulating valve connection, installation and debugging. Pneumatic actuators can be divided into two types: single-acting and double-acting. There is a return spring in the single-acting actuator, while there is no return spring in the double-acting actuator. Among them, the single-acting actuator can automatically return to the open or closed state initially set by the valve in the event of loss of origin or sudden failure.

The pneumatic control valve is divided into two types: air-opening and air-closing according to the active form, the so-called normally open type and normally closed type. The air-opening or air-closing of the pneumatic control valve is usually through the positive and negative action of the actuator and the valve state structure of different assembly methods.


What Is The Function Of The Pneumatic Control Valve?

It can be used to adjust the flow rate and pressure of the valve medium, convert the air pressure into motion and use the air as the control medium to open, close or adjust the flow rate as required by the pneumatic actuator.

Applications Of Pneumatic Control Valves

  • Shipbuilding
  • Power Plants
  • Food & Beverage
  • Wastewater Treatment
  • Boiler
  • Paper & Pulp
  • Chemical

If you have any demand for pneumatic control valves, feel free to consult us at for a suitable valve solution.


What Is COVNA Pneumatic Actuated Knife Gate Valve?

Pneumatic actuated knife gate valve is a relatively complex automatic control, which is composed of a variety of pneumatic components and valve bodies. It is suitable for medium pipelines such as syrup, paper pulp, sewage, coal slurry, ash, dust, and slag-water mixture.

In the past, such as in paper industry applications, viscous pulp can get stuck in the valve seat of ordinary gate valve and prevent the valve from closing, causing the valve seal to leak, but the knife gate valve is specially designed so that the valve has a sharp edge, which can be cut open viscous media and seal to prevent leakage.

Pneumatic actuators are the most affordable and economical way to drive a knife gate valve. Because knife gate valves are only suitable for on-off use, not media modulating applications, the design features are ideal for installing pneumatic actuators.

Pneumatic knife gate valves are mostly used in occasions requiring quick shut-off or opening, the gate has a shearing function, which can scrape off the adhesive on the sealing surface and automatically remove the sundries. Due to this special design, pneumatic knife gate valves are very effective in applications involving viscous fluids, slurries and other media.

In this article, I will introduce to you the advantages and characteristics of COVNA Pneumatic Knife Gate Valves

In COVNA, pneumatic knife gate valves are available in Cast iron, carbon steel and stainless steel. The pneumatic actuator has linear series and an imported actuator series to choose from.

The advantages of our pneumatic knife gate valve are ultra-thin design, full diameter flow, not easy to leak, easy disassembly and assembly, movable sealing structure, strong cutting force, good sealing performance, strong wear resistance, automatic compensation, long life, not easy to accumulate and low torque.


Applications Of Pneumatic Knife Gate Valves

  • Cement plants
  • Solid waste treatment
  • Paper and pulp
  • Wastewater treatment

If you have any demand for pneumatic knife gate valves, feel free to consult us at for a suitable valve solution.

Pneumatic Actuator Valve For Reverse Osmosis System

Reverse osmosis (RO) system uses the principle of reverse osmosis to remove mainly dissolved salts from water while removing some macromolecules and small particles etc. that were not removed in the previous stage. The pneumatic actuator valves can play a lot of roles in this system.

It is mainly driven by pressure, forcing the solvent in the solution to separate from the solute by the retention effect of the semi-permeable membrane.

In the following, we will introduce you the valves that can be used in reverse osmosis systems. We hope this will help you understand and select the right valve.

Pneumatic Butterfly Valve

The main advantages of pneumatic butterfly valve are simple structure, small volume and weight, can also regulate the flow of media. Fluid resistance is small, medium and large diameter pneumatic butterfly valve full open effective flow area is larger, opening and closing quickly and effortless, disc wrench rotation 90 angles to complete opening and closing.

Pneumatic Ball Valve

Pneumatic ball valves are mainly used in pipelines to cut off fast, distribute and change the flow direction of the medium.

The switch is light, small in size, can be made into a large diameter, can be sealed, has a simple structure, and is easy to maintain.


Check Valve

The main function of the check valve is to prevent the backflow of the medium, to prevent the reverse rotation of the pump and the driving motor, and discharge the medium into the container. It is very suitable for use in the RO system to prevent the backflow of the water medium.

Globe Valve

It is a very important cut-off class valve, whose seal is made by applying torque to the valve stem, which exerts pressure on the valve flap in the axial direction so that the sealing surface of the valve flap fits closely with the sealing surface of the valve seat and stops the medium from leaking along the gap between the sealing surfaces.


COVNA Automated Valves For Brackish Water Desalination

What is Brackish water desalination?

Brackish water desalination is actually the desalination of salt water, so that the salt water is desalinated or treated to meet the drinking water standard.

There are many methods of desalination of brackish water and seawater, mainly distillation, electrodialysis and reverse osmosis. At present, reverse osmosis and electrodialysis are mostly used in the desalination of brackish water. The reverse osmosis method has a tendency to catch up with the latecomers due to its low investment and low energy consumption.

Using reverse osmosis technology, because chloride is not used for other substances, it can be removed by a certain filter material, and the removal process of chloride is generally treated by reverse osmosis technology, and this step will use automatic valve treatment

Below, we will introduce COVNA automated valves that can be used for brackish water desalination.

Pneumatic Control Valve

Control valve can precisely regulate the flow, pressure and temperature of the medium, making your automation easier, helping you control the medium more accurately, without electricity, and safe and explosion-proof. Enable industrial automation to help you control flow rate remotely.


Electric Ball Valve

Electric ball valves are available in stainless steel, UPVC or carbon steel materials, and are used for the regulation and control of various fluids. Among them, electric V-shaped ball valves are especially suitable for shut-off media containing fibers and tiny solid particles. Strong vibration resistance and easy installation. Performance indicators are better than similar products.


Pneumatic Butterfly Valve

The pneumatic butterfly valve can be opened and closed quickly with only 90 rotations, and the operation is simple. At the same time, the valve has good fluid control characteristics. Commonly used are pneumatic flange butterfly valve and pneumatic wafer butterfly valve.


Check Valve

Relying on the flow of the medium itself, the valve flap is automatically opened and closed to prevent the backflow of the medium, also known as check valve and one-way valve.

COVNA Valves For Industrial Fogging Systems

Fogging system is to achieve atomization of liquid, which can be used in fire fighting industry, dust-free treatment equipment, mosquito repellent fogging equipment and other automated industries and equipment. Valves assist in the transfer of liquids to the fogging system and increase productivity. The process of atomizing liquids requires high pressure, so we would recommend the use of high-pressure valves for atomization systems.
In this article, we will introduce you to the COVNA high-pressure valve series, which we hope will help to understand and select the right valve.

High-pressure Ball Valves

The body thickness of the high-pressure ball valve is 2 times thicker than that of a normal ball valve. When subjected to the impact of high-pressure media, it can still maintain stability and normal operation. The thicker body keeps it from blowing up, thus ensuring the proper operation of the project. The high-pressure ball valve can withstand pressures up to 400 bar, so it will be your valve of choice.
The high-pressure ball valve can be driven by electric or pneumatic actuators, thus enabling remote control of the valve.

High-pressure Butterfly Valves

High-pressure butterfly valves are generally referred to as triple eccentric hard seal butterfly valves. It can withstand pressures of up to 40 bar. The size range is up to 16″, which makes up for the lack of ball valves (the maximum size of high-pressure ball valves is only 2″). The high-pressure butterfly valve is available with a choice of clamped and flanged connections.
Likewise, the high-pressure butterfly valve can be driven by electric actuator or pneumatic actuator.

Above is the introduction of high-pressure valves that can be used in atomization systems. If you have any need for valves, welcome to consult us for the best valve solution and budget cost.