Do check valves work? Are they worth it?
Tired of water or pressure loss in your piping? Using check valves could be the solution to your problem. But before you get one, there are things you should know. In this blog, we will discuss what is a check valve, how check valves work and types of check valves. We will also cover benefits of using check valves and troubleshooting common issues with check valves.
What is a Check Valve?
Check valves are one of the most important valves in any fluid system, as they prevent backflow of fluid at pressure differential. This type of valve is a non-return valve that closes off flow in one direction when pressure differential exceeds a specified value. Check valves are self-operating and open or close in response to pressure differential.
Butterfly check valves consist of two flaps which rotate around a hinge to open or close in response to pressure differential. They are easy to open and close and have good flow rate and pressure control ability.
They are used in aircraft and aerospace due to their ability to handle high vibration, large temperature extremes, and corrosive fluids. However, check valves need a minimum differential upstream pressure to operate automatically. Hence, it is essential for them to be properly designed and installed in valves for effective operation.
Types of Check Valves
– Check valves are electronic valves that hold back the flow of fluid in one direction. They are self-operating valves that open in response to pressure differential, preventing backflow of fluid.
– Different types of check valves may be encountered in various applications. Butterfly check valves consist of two flaps that open and close in response to pressure. The closing mechanism of a butterfly valve is usually held in place by a spring or weight, depending on the type of valve used.
– Cracking pressure is required to open a check valve automatically. This is ensured by cracking pressure in the line closing the valve. If water or other fluid is leaking through a check valve, it will result in cracking pressure.
– Some check valves are opened by a difference in pressure between the inlet and outlet side of the valve. When water flow is stopped, this difference reduces over time, causing the valve to open automatically. These types of check valves ensure water flow does not reverse back into the source of water flow when it is shut off or stopped.
– Another type of check valve is the ball check valve. This type of valve consists of a ball and socket joint that opens or closes based on pressure differential across its face. However, these types of valves are expensive and prone to corrosion, so they are not commonly used anymore.
How Do Check Valves Work?
A check valve is a valve that closes and opens in response to pressure differences. This self-operating valve relies on a pressure differential to open or close the valve when necessary. Check valves are made of two ports—an inlet and an outlet—and a closing mechanism, held in place by a spring, counterweight, or gravity. The closing mechanism in check valves is usually held in place by a loaded spring, a counterweight, or gravity. Check valves are used in high-vibration, large-temperature extremes, or corrosive fluid applications, such as aircraft and aerospace. The functioning of check valves is based on the pressure-flow relationship of flow through piping systems: The pressure drop across the valve opening causes flow to decrease and the valve to open. When flow increases past the desired level, the pressure drop across the valve closure causes flow to increase and the valve to close.
Check valves are one of the most common types of valves used in piping systems. They help ensure that flow stays constant and steady within piping systems.
Choosing the Right Check Valve for Your Application
Check valves are one of the most-used pressure-regulating valves in aerospace and manufacturing industries. They provide an effective way to control pressure in piping or piping systems.
They are designed to open or close in response to differential pressure, maintaining a consistent pressure regardless of flow rate or flow direction. Depending on the type of application, check valves can be used for water supply, sewage treatment, air flow, and water hammer protection among others. Before purchasing one, it is important to understand the purpose of the check valve in your pipeline and consider factors such as type of material it will be exposed to, connection point size, max pressure, cracking pressure, and installation orientation. Also essential is checking the envelope dimensions and accessibility for inspections and repairs. These valves are useful in aircraft and aerospace where high vibration, large temperature extremes, or corrosive fluids are present.
Benefits of Using Check Valves
– Check valves are vital safety device in fluid-handling systems. They are used in high-vibration, large-temperature extremes and corrosive fluid environments.
– Butterfly check valves open and close quietly, making them ideal for home applications such as heaters and air conditioners.
– Pump check valves act as a one-way safety device that prevents reverse flow in piping systems. These valves have no requirement for an operator or external control, and they are powered by pressure differential between the inlet and outlet ports. The flow rate of fluid can be controlled easily using check valves.
– The types of check valve available include ball check valve, diaphragm check valve, sleeve check valve, disc check valve, disc actuator check valve and ball-check actuator check valve (BCAC).
– It is essential to understand the characteristics of different types of check valves before deciding on the type of one to use.
– It is important to ensure that the check valve is properly fitted to the piping system for optimal performance and efficiency of the flow control mechanism.
Troubleshooting Common Issues with Check Valves
– The working principle of a check valve is that it requires a minimum upstream pressure (pressure differential between inlet and outlet) to open the valve and allow fluid flow.
– When there is a back pressure (flow attempting to move from the outlet to the inlet), the check valve will close automatically.
– If the check valve does not open when water or other fluid is flowing through it, one of two conditions may be occurring: either air is blocking the flow, or water has accumulated in the valve and caused closed position.
– When checking valves are functioning properly, one should hear water running through them, but no back-flow or banging noises. However, one must also check for proper operation of check valves in water pipelines. This includes making sure valves are clean and properly lubricated as well as regularly inspecting and replacing faulty valves. If this essential step isn’t followed, it could lead to a failure of a swing check valve or an open check valve.
Frequently Asked Questions
How do you check a poppet valve’s operation?
To check a poppet valve’s operation, you will need to measure the pressure differential between inlet and outlet ports and observe the valve’s response.
Poppet valves are variations of ball check valves, which are held in place by a spring and open when the cracking pressure is reached. The travel of the poppet is controlled by a stop on the end of the poppet legs which is shouldered onto a washer. Check valves open automatically when the inlet port pressure is greater than the outlet port pressure, and closes when the pressure differential decreases.
Silent check valves close quickly and smoothly to prevent water shock. To check a poppet valve’s operation, measure the pressure differential between inlet and outlet ports and observe the valve’s response.
Uncovering the Weight of Gate Valves
Conclusion
In short, check valves work by closing off one flow of fluid or gas in an open channel when pressure in the channel rises too high. While check valves are commonly used in water-based systems, they can be used in a range of fluid-flow applications. So, next time you’re faced with a valve-related problem, check valves may be your solution. You can learn more about valves in our blog ‘Valves: A Compendium of FAQs.’
Mr. Jahangir Alam is an Electrical & Electronics Engineer with a wide range of experience in several fields of Engineering. He finds engineering articles to be very interesting, and that is why he likes to write them. To know more about him, please click here.