Check Valve Types, Applications and Selection Criteria

Let’s take a look at the various types of check valves and discuss how they work, how they’re used, and how to choose the right type.
Systems designed to allow fluid media to flow in only one direction typically have check valves.Examples of such systems include sewage pipes, where waste can only flow in one direction.Check valves are also used where back flow can cause equipment damage.Before we get into the different check valve types, applications, and selection criteria, let’s first understand how check valves work.
A check valve or check valve is a device that restricts the flow of fluid in only one direction.Check valves have two ports, an inlet and an outlet, and are designed to prevent backflow of fluids in various industrial systems.There are different types of check valves, and they differ in the mechanism that causes them to open and close.However, they all rely on differential pressure to allow or restrict fluid flow.Unlike other valves on the market, check valves do not require levers, handles, actuators or human intervention to function properly.They are cheap, effective and easy to deploy.That is, the check valve will only operate when there is a pressure differential between the inlet and outlet.The minimum differential pressure that the system must exceed in order for the valve to open is called the “cracking pressure.”Depending on the design and size, the value of this cracking pressure varies with the check valve.The valve will close when there is back pressure or the cracking pressure is higher than the inlet pressure.The closing mechanism of a check valve varies by design, i.e. a ball check valve pushes the ball towards the orifice to close it.This closing action can also be assisted by gravity or springs.
As mentioned earlier, there are several types of check valves, each designed for its unique application.However, a type called a spring-loaded in-line check valve is used in a variety of industrial settings.Spring-type in-line check valves have springs, valve bodies, discs and guides.When the inlet pressure is high enough to overcome the cracking pressure and spring force, it pushes the valve flap, opening the hole and allowing fluid to flow through the valve.If back pressure occurs, it will push the spring and disc against the hole/orifice, sealing the valve.The short travel distance and fast-acting spring allow for a quick response during closing.This type of valve can be installed horizontally or vertically, in line with the system, and therefore must be completely removed for inspection or repair.The following are other types of check valves:
Other types of check valves include globe check valves, butterfly/wafer check valves, foot valves, and duckbill check valves.
Check valves are used in almost all industries where fluid must flow in one direction.These valves are also used in household appliances such as washing machines and dishwashers.Depending on the design and mode of operation, check valves can be used for any of the following use cases:
Some factors to consider when selecting a check valve include: Compatibility of the check valve material with the fluid medium.
Check valves are popular devices in industrial settings that are not only cheap and reliable, but also relatively easy to use.When purchasing a check valve, make sure you understand your unique needs and check valve selection criteria.Also, make sure you understand the installation requirements to avoid flow direction issues or damage to your system due to pressure build-up.
Charles Kolstad has been with Tameson since 2017 and is from the United States of America.He holds a degree in Mechanical Engineering from St. Thomas University, Minnesota, USA.He works remotely while traveling in Europe, Asia and the Americas.However, he does visit Tameson’s headquarters from time to time to meet new members of the team and work from the office.