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When working with gases, safety and reliability are priorities. You need to make sure that the gas is flowing where you want it to, without exception. This is where a CO2 check valve comes in. With a check valve, you are assured there is no backflow of any of the carbon dioxide in the system.

In this article, we’re going to look at CO2 check valves in greater detail. We’ll examine what these valves are, where they are used, and how the different types work. Read on to discover more.

What Is a CO2 Check Valve?

CO2 check valve is a component of your system that enables carbon dioxide gas to flow in a single direction. When the carbon dioxide (CO2) gas flows in the intended direction, the valve permits the gas to pass through. If carbon dioxide is flowing the opposite way, against the intended flow, the valve does not permit it to pass through. The valve also prevents other materials, such as water or oxygen, from flowing back into the system. Because of this, the component is sometimes referred to as a non-return valve, one-way valve, or reflux valve.

Unlike other types of valve components, there is no handle or wheel attached. This is because the component is not designed to be operated or controlled by human users or to regulate the flow rate of the gas. It simply sits in the system and ensures that CO2 gas is flowing in the correct direction.

What Are CO2 Check Valves Used For?

A CO2 check valve may be used in a number of different applications, from industrial and commercial usages to medical and hobbyist applications. Here are some of the most common:

  • Refrigerating and cooling for commercial and industrial systems
  • Extinguishing and controlling electrical fires
  • Creating inert environmental conditions for chemical reactions
  • Developing ultra-hard metal casting molds
  • Serving as a shield gas for larger-scale MIG/MAG welding projects
  • Enhancing welding efficiency and effectiveness
  • Stripping paint from surfaces with a high-pressure spray
  • Acting as a raw material during the production of methanol and other chemicals
  • Aiding oil extraction from wells and other fossil fuel infrastructure
  • Removing excess rubber following a process of molding
  • Freezing foodstuffs ready for transportation
  • Carbonating sodas and other drinks
  • Preventing fungal and bacterial contamination in drinks and foodstuffs
  • Decaffeinating coffee products
  • Supporting efficient canning and sealing of foodstuffs
  • Simulating respiratory oxygen/CO2 mixtures in medical applications
  • Pressurizing aerosol cans
  • Neutralizing basic mixtures and compounds
  • Enhancing rates of photosynthesis by optimizing greenhouse and hothouse environments
  • Augmenting plant growth in aquariums by optimizing the water conditions
  • Dissolving stubborn stains and marks during dry-cleaning

In addition to the above applications of a carbon dioxide system, individuals and businesses may find themselves dealing with carbon dioxide for other reasons. For example, excess carbon dioxide can be harmful to humans and animals and will need to be removed using a reliable system. CO2 check valves may be necessary here to prevent carbon dioxide backing up and putting health and safety at risk.

Different Types of Check Valves

There are many different types of CO2 check valves available to you. The valve you choose may depend on your specific application or on the pressure of your system.

Ball Valves

A ball within the valve moves in the same direction as the carbon dioxide flow. When the CO2 moves in the intended direction, the valve remains open. If it reverses, the ball travels backward, closing the valve.

Swing Valves

In this valve, a flat surface replaces the ball. When the flow of gas is in the right direction, the valve remains open. If it moves the other way, the valve automatically closes. This type of valve may also be known as a gate valve, as there is a gate component that swings into position if pressure is applied in a specified direction.

Lift Valves

Lift valves work in much the same way as swing valves, but they tend to operate vertically rather than horizontally. When pressure builds up behind the plate, the valve is lifted, allowing the gas to travel through the opening in the intended flow direction. Any movement in the other direction will close the valve. Lift valves can still be used in horizontal sections of piping, but the gas may need to be redirected so that it flows vertically into and out of the valve.

Double Valves

Double check valves are essentially two check valves positioned together within a system. Each valve can operate independently, but the two valves together provide a fail-safe, ensuring the system is doubly protected. The system components are redundant, so even if one fails, the other will keep on working to prevent gas backflow.

Two-Way Valves

Some specialized applications may require a two-way check valve. In this system, there will be two gas inputs at different pressures. These gas inputs feed into the valve and manipulate a shuttle component within the valve body itself. The shuttle will be pushed away from the highest-pressure gas inlet toward the lowest-pressure inlet so that the higher-pressure gas is permitted to flow into the outlet. This shuttle component then performs the standard checking function, preventing gas from flowing backward to the inlet.

Low-Pressure Valves

All  the valves listed above work on the same principle. The pressure of the gas flowing in the desired direction opens the valve, while pressure in the opposite direction closes it again. But what happens when the pressures involved are much lower? For a normal valve, this is a problem, as the pressure is not enough to manipulate the checking mechanism. A low-pressure valve provides the answer, remaining operational even in systems with minute gas pressure.

Explore CO2 Valves in the Sherwood Valve Range

In the Chemtech product range, you’ll find a variety of different Sherwood Valve products, including CO2 check valves. Take a look at the pieces in the range, examine the different specifications, and make your choice. To discover more, reach out to our team directly.