Sanitary Spring Check Valves- Seal Type Options

February 6, 2015
Sanitary Disk Type Check Valve

Waukesha Sanitary Disk Type Check Valve

Today we’re going to revisit a topic we’ve discussed previously on this blog- spring check valves. A check valve is a device that is used to prevent reverse flow in a pipeline. Check valves come in a variety of types, with the two most common in the sanitary process industry being the ball and spring check types. Today we’re going to specifically focus on selecting sanitary spring check valves and some unique features you may want to keep in mind for your next application.

One of the most common sanitary check valves we use on a day in and day out basis is Waukesha Cherry Burrell’s W45 spring check valve. We like to use this valve not only because it is available with a variety of springs, elastomers, and surface finishes, and also because it offers two different seal designs for the spring loaded seat- a standard O-ring seal and a Tri-ring seal option. So which seal type should you use for your application? Let us explain.

The O-ring seal design is ideal for general purpose applications that require cracking pressure and pressure drop across the valve to be as low as possible. This is a general duty seal designed for a wide range of products and laminar flows.

So what are you to do in more violent applications, you might ask. What kind of seal should you look for if you have high flow velocities, such as those found in CIP applications, or if you are trying to prevent backflow of thick, viscous, or sticky products that tend to crystalize on sealing surface? Well, we have an answer for that- the Tri-ring seal design. If you order your Waukesha W45 check valve with a Tri-Ring stem, it is supplied with a heavier spring. The heavier spring is ideal for applications where the fluid velocity exceeds 5 ft./second. The geometry of the Tri-Ring stem also makes it ideal for liquid sugar applications where sticky products can have a negative impact on valve performance.

So which one should you use? Well, it depends largely on your process application. Fortunately, if you pick the wrong seal type initially, or even if you have an existing W45 check valve with O ring seal, Tri-Ring replacement stems are available from Holland Applied Technologies and supplied as ready to install cartridges.
So there you have it- one more tool you can use to fine tune your high purity process to achieve optimal performance. As we’ve focused on throughout this blog, selecting the right product- as well as the right product features-for your application is essential for success in the challenging sanitary fluid handling industry. While the correct products sometimes come with a higher upfront cost, by using high quality products specifically designed for your application, you can maximize both service life and performance, as well as minimize total cost of ownership- saving far more than the high initial investment in the long run. For more help with your next sanitary check valve or high purity processing need, contact a Holland Sales Engineer today.