At Triplex, not only do we sell a lot of sanitary pumps, we are also the Midwest’s leading supplier of sanitary ball valves. One of the most common types of valves we see used in sanitary fluid handling applications are sanitary ball valves, often with “cavity filled seats” or “cavity fillers”. So what is a cavity filled ball valve? Let’s dig a little deeper.
Let’s start by talking briefly about why we specify ball valves for high purity process applications in the first place. Sanitary ball valves offer inline full fluid flow with almost no pressure drop. This makes them perfect for handling viscous liquids or liquids with suspended solids. We see them used most often in chocolate applications and high purity water systems. I know- quite the range, right? Sanitary ball valves are simple, quarter turn devices that can be welded and serviced inline.
Sanitary ball valves are also highly configurable. Available in 2-way, 3-way, and even 4-way divert style bodies. Ball valves can be supplied with a notched V ball for flow control and are easily actuated and outfitted with control tops for position feedback and throttling.
But back to the main topic of this post- what is a cavity filled ball valve? When talking to a customer about a sanitary ball valve the question always comes up- how do you clean behind the ball? And while there are a few different options, the most common solution has been to use a cavity filled ball valve. A cavity filled ball valve refers to a seat that fills the cavity around the ball. The ball is completely encapsulated by the seat which prevents product from getting behind the valve in the first place. This is ideal for applications where cross contamination is a concern or where product can crystalize on a seal face.
Cavity filled seats are most typically offered in PTFE, but are also available in Polyether Ether Ketone (PEEK), and Stainless Steel Impregnated Teflon.
Not every sanitary valve application is the same. While ball valves aren’t ideal for ultra-high purity applications, they do offer cost effective, unobstructed flow for high purity fluid handling applications. And if you’re running a viscous product or are especially concerned about cross contamination, make sure you specify a ball valve with cavity filled seats. And as always, if you have any questions about valving for your high purity process application, contact a Triplex Sales Engineer today!