Check valves are one of the most common types of valves in use today. In this post, we’ll discuss how they work, what they’re great for, advantages, and disadvantages of use so you can get a better understanding of this commonly misunderstood valve.
WHY CHECK VALVES?
The main function of a check valve is to stop flow from travelling backwards into a system. If check valves are not in place, pumps and other pieces of equipment can sustain damage, not to mention, fluid would go into places it shouldn’t.
HOW THEY WORK
Check valves rely on flow to open and close. As fluid passes through the line in the desired direction, the disc (ball, or flap, depending on the valve’s design) opens. But as flow decreases or reverses, the valve quickly closes.
Check valves are used in many industries across a plethora of applications, some of which include:
- Water/wastewater treatment
- Injection lines
- Washdown systems
- Cooling towers
- Condensate lines
- Many more…
The check valve’s operation is completely self-automated. Therefore, should a facility lose power, the valve would still function, preventing damage to pumps and other equipment, as well as other problems up stream.
Noise (slamming), water hammer, and reverse flow are common problems with check valves. It is very important to note, however, that these problems generally occur because of improper sizing and/or selection for the application.
These types of valves commonly (and mistakenly) selected/sized as an on/off valve would be. Doing so could cause premature wear, high pressure drop, and increased expenditure of pump energy as it works harder to satisfy the system.
If you’re experiencing issues with a check valve, or need to select a new one for your process, talk to an engineer experienced in selection/sizing of these types of valves. Doing so will help your system perform at its highest efficiency, while requiring a lot less maintenance.