Swing check valves are by far the most common check valve in any industry. They are often a lower-cost solution and may work in many horizontal flow applications. However, it’s important to understand the differences between a swing check valve and a spring check valve. In this article, we’ll cover some basic differences between these two types of inline check valves. We will also discuss some of the advantages of using a spring check valve over a swing check valve.
1. One difference between these types of check valves is that the they allow and prevent flow. A swing check valve uses a flapper that ‘swings’ off the seat to allow forward flow and then swings back onto the seat when the flow is stopped. In contrast, a spring loaded check valve incorporates a spring to assist in closing the valve. Learn more about spring check valves!
2. Swing check valves are limited in the orientation in which they can be installed. Swing check valves can only be installed in horizontal flow applications, which greatly limits the installation orientation. While swing check valves do offer a larger flow capacity, they do not always fit in existing piping configurations. On the other hand, spring loaded check valves can be mounted in any flow orientation with the right spring selections. So if you have a process skid, a difficult space with challenging dimensions, or even unique direction of piping, choosing a valve with the right spring setting (a.k.a spring cracking pressure). This type of check valve creates more possibilities for finding the right solution for your specific flow control application.
3. A spring loaded check valve will help minimize effects of water hammer, while a swing check valve can exacerbate the issue. Any water hammering effects present in a piping system can potentially be amplified by a swing check valve. Spring check valves are considered “silent check valves” by utilizing a spring to assist the poppet in closing the check valve prior to fluid flow reversal. The following is a basic example to explain the concept of water hammer.
In an application where you have a line with water in it and you have a check valve. Downstream of that check valve, you have a lever handle quarter turn ball valve. Let’s say water is flowing and someone shuts the quarter turn ball valve abruptly. This can produce a pressure wave flowing through the piping – this is what is known as water hammer. With a swing check valve specifically, the flapper on that valve will be open until that pressure wave returns back to the swing check. The pressure wave can cause the flapper to slam shut and cause excessive wear within the swing check valve and other piping system components. Conversely, a spring loaded check valve will help minimize, and in some cases, eliminate the effects of water hammer because the spring in the spring check closes before the pressure wave gets there.
We hope this clears up any confusion you may have around the differences between these different type of check valves and that you learned the advantages offered by spring check valves. All the valves Check-All Valve manufactures are inline spring loaded poppet style check valves. Our expert staff can answer any questions you may have. Use the comments to post your questions or tag us on social media. Stay tuned for our next article!