There are many different types of valves, all with slightly different purposes. One of the most common and useful valves available is the swing check valve. This valve is designed to transport fluids in only one direction. But how does it work and what are its practical applications? Keep reading to find out! Keep in mind, this article focuses on PVC swing check valves; metal swing check valves can get a bit more complicated.
How Does a Swing Check Valve Work?
Swing check valves work a little like a butterfly valve. They have a disc inside that covers the opening of the valve. That opening has to be clear in order for anything to pass through. The disc is attached to a hinge, so the disc can swing open or closed when liquid hits the disk. It's kind of like a circular door. The direction of the flow is the most important thing when using these valves.
When liquid is traveling in the desired direction, the pressure of the flow pushes the door open, allowing liquid to pass through. When liquid travels in the wrong direction, the opposite happens. The force of liquid coming back through the valve pushes the disc against its seat, closing off the valve. When installing a swing check valve, it is vital that it opens when liquid is passing through the desired direction. If you install one of these valves and no water goes through, then it is the wrong way around and must be reinstalled. If your swing check valve has a true union design, it can easily be removed from the pipeline.
These valves are available in many different forms. Metal swing check valves are often seen in heavy industrial use. However, a PVC swing check valve can often handle the same jobs and will be much less expensive.
What Is a Swing Check Valve Used For?
As stated before, a swing check valve is for when you want fluid traveling in only one direction. Another important detail about these valves is that they require no external power, which makes them ideal for a wide range of applications. They also let fluid pass through without slowing down the flow much when fully open.
One of the most common uses of a swing check valve is the flapper valve in a flush-toilet mechanism. This allows water to enter from the bottom of the tank, but prevents it from draining out the same way. Swing check valves are the most common type of valve in water and wastewater pumping systems. In any situation where backflow could cause problems, swing check valves are the go-to.
Swing Check Valve vs. Spring Check Valve
One iteration of the swing check valve is a spring check valve. These valves function in the same way as swing check valves, but they have a spring to stay closed when there is no flow in the correct direction. That means that as soon as fluid stops flowing through, the valve claps shut.
It is easy to get swing and spring check valves confused, but they do serve different purposes. Swing check valves are forced close by backflow and spring check valves are closed by default, requiring more pressure to open their door and allow fluid through. Make sure you get the one you need! Many online forums debate on which are best for certain jobs. Checking those could help you decide which you need.
Swing Check Valve Installation
Hopefully you know a little more about swing check valves now. PVC swing check valves come in a range of sizes and designs for every job imaginable. There are small ones for DIY jobs and larger industrial-grade ones for heavy-duty work. Visit our swing check valve product page to see our full selection of swing check valves.