Did you know that check valves are among the most commonly used valves across all industrial processes? With a simplistic design and straightforward function, check valves can be found in most applications and systems. In this informative article, MGA Controls provides readers with an understanding of how check valves work and their most common operations.

How does a check valve work?

The purpose of a check valve is to allow fluids (gas or liquid) to flow in one direction, whilst preventing backflow and minimising chances of leakage. Also referred to as non-return valves, they have two openings in the body – one for the fluid to enter and another to allow the fluid to leave.

Because of their simple design, check valves are generally operated without automation or human interaction. Instead, they rely on the flow velocity of fluids to open and close the valve. The minimum upstream pressure required for this function is commonly referred to as ‘the cracking pressure’.

Interestingly, most check valves are specifically designed with this figure in mind. Depending on the size and type of check valve, the cracking pressure will vary between 1 psi to 5 psi.

What is a check valve used for?

There are six different types of check valves, all of which have different uses and functions. Specific uses of check valves depend on the configuration of components. For example, ball check valves must also be placed so that the direction of the lift is vertical. However, a swing check valve must be placed to ensure the disc is always closed freely and positively by gravity.

Although the goals of check valves are ultimately quite singular, the specifications to achieve them can often differentiate. If you operate severe applications with high flow characteristics, you may opt for either nozzle check valves or tilted disc check valves. Whereas silent check valves are most suitable for noise sensitive applications, dual disk valves should be considered if space and cost are major concerns.
The reason why there are so many different types of check valves is due to the range of material options available. As a result, this allows for check valves to be utilised in a variety of different markets and operations.

Check valve operations

As check valves are manufactured from hard-wearing materials, they can operate in a wide range of applications. While check valves can be commonly found in irrigation, potable water or wastewater applications, their interchangeability means that they applied across different industries.

For example, many fluid systems that are used in chemical and power plants will be utilising industrial check valves. Whereas the nuclear industry would look to implement non-return valves in an array of different applications ranging from water control systems to monitoring and sampling systems.

Additionally, there is a use for check valves within the aircraft and aerospace industries where either high vibration, larger temperature extremes or local fluids are present. Outside of individual industries, check valves are also used in operations where multiple gases are mixed into one gas stream. This involves having one valve on each side of the individual gas streams to prevent mixing.

Here at MGA controls, we stock a comprehensive range of industrial check valves. Made from WRAS approved materials by leading manufactures Val-Matic and Singer, you can be sure that your check valves are robust, reliable, hard-wearing and capable of operating in any environment.

For more information regarding our check valves, please call us on 01704 898980 or send us an email at sales@mgacontrols.co.uk.