Fluid Controls Ltd is one of the UK’s leading distributors for pressure control

Check Valve Types

What is a double check valve?

When it comes to fluid control and plumbing, precision is paramount. In fact, without it, you can’t guarantee a product will perform and function as you’d like. Precision is especially important with systems that deal with chemicals, water or any other liquid substances. This is where double check valves come in as they are indispensable components that safeguard against contamination and backflow within systems.

In this article, we will look at double check valves in more detail and answer any questions you may have such as, ‘what is a double check valve’ and ‘what does a double check valve do’. While also looking at the main uses and purposes of double check valves, we will take a closer view of some of the options available here at Fluid Controls.

What is a double check valve?

Double check valves are usually two single check valves that are linked together to provide a failsafe backup to one of the check valves failing. Double check valves have screws on each side making the valve port accessible so it can be opened and cleaned as typically debris can build up over time. 

What does a double check valve do?

Double check valves, which may sometimes also be referred to as double-check backflow preventers, is a device that has been designed to prevent the backflow of contaminated water. It also works with other undesirable substances to prevent them from entering a clean water supply. 

Double check valves work as a type of backflow preventer that consists of two independent spring-loaded check valves within a single body. Usually, these check valves are installed in series, which means that if one valve were to fail (for whatever reason) then the second valve can act as a backup and prevent backflow. 

Main purposes and uses of double check valves

As we’ve already discussed, double check valves are used mostly for backflow prevention but there are also some other main purposes and uses that we will explore below. 

Backflow prevention

So we know that double check valves are mostly used for backflow prevention. But what does that mean and how does it work? 

The primary function of double check valves is to prevent the reversal of flow in a water supply system. Backflow can occur when water pressure suddenly drops or when there is a cross-connection between a clean water supply and a potentially contaminated source. An example of this is an irrigation system or a chemical tank. 

Therefore, by having double check valves in place, they act as a robust barrier against backflow and can ensure that even if one were to fail the other could ensure that the water supply remains safe to use and offers contamination control. 

Regulatory compliance

Due to how significant a role double check valves play in ensuring water safety and quality, in many countries, including the UK, there are strict regulations and standards in place. Often double check valves are required by law for use in specific applications, such as during the protection of potable water systems. 

Therefore, double check valves are essential to help businesses meet regulatory compliance and effectively prevent backflow and preserve water quality. 


Another main use of double check valves comes from its versatility. They are versatile components that are suitable for a wide range of applications. They’re commonly used in both residential and commercial settings which makes them popular choices. Some of the most common uses of double check valves include boilers, lawn irrigation systems and commercial dishwashers.

Uses of double check valves 

Let’s take a look at how double check valves can be used in a range of different settings. 

Industrial and commercial applications

As mentioned above, double check valves are commonly used in commercial dishwashers. But this isn’t the only place you’ll find them frequently employed in industrial and commercial settings. In these environments, protecting a clean water supply is essential for public health and safety. Therefore, double check valves are used in food and beverage industries, chemical processing plants and manufacturing facilities. 

Boiler systems

Another common use of double check valves includes heating systems and boiler applications. Here, they’re essential to prevent the backflow of heating chemicals or contaminants in the potable water supply. This is a particularly crucial usage when maintaining the safety of heating systems in our homes and commercial buildings. 

Now that we’ve covered the main questions of ‘what is a double check valve’ and ‘what does a double check valve do’, you need to know where to get double check values. 

Fluid Controls is a trusted supplier of fluid control solutions in the UK, offering a wide range of high-quality double check valves that meet the requirements and needs of various industries. We also have an extensive range of fluid control products for industrial applications, from compressed air and pneumatic systems to pressure control valves. 

Find out more about the products we have available by getting in touch with our contact sales office at 0118 970 2060 or email fluid@fluidcontrols.co.uk.

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