Sanitary Angle Seat Valves- What are they and when should I use them?

One of the calls we get most often at Triplex Sales is to help our customers identify the right valve for their high purity process applicaiton. This isn’t always an easy answer- we need to help our partners find a way to balance functionality, sanitation requirements, automation requirements, and cost to enable them to control their process. In today’s post, we’re going to take a look at angle seat valves, specifically Burkert’s line of sanitary angle seat valves, why we use them, and where.

To start, what is an angle seat valve? Well, an angle seat valve is very similar to a ball valve, but instead of using a ¼ turn ball, we use an angled body and plug to control flow. The plug seats against a landing in the body creating a seal with the PTFE seal on the valve plug. The simple construction allows us to handle a wide range of fluids, including thick or thin liquids, as well as particulate laden liquids. Angle seat valves are typically pneumatically actuated and have about the same pressure drop as a ball valve. Angle seat valves are available in ¼”-2 ½” and in a variety of sanitary connections, including tube weld ends and Tri-Clamp ends.

Yep. Angle seat valves are really that simple.

So given that an angle seat valves are a pretty simple on/off valve, why would we use a Burkert angle seat valve vs. a ball valve? To start, because we don’t have stem packing, angle seat valves have far less leaks and require less maintenance than a ball valve. In fact, Burkert guarantees their angle seat valves for 5 million cycles on water and 2 million cycles for steam.

With an angle seat valve, especially Burkert’s, we’re able to easily automate the valves. Angle seat valves use compact linear actuators that stroke up and down, whereas ball valves often use balky rank and pinion actuators. This means we get a significant space savings when using an automated angle seat valve vs. an automated ball valve.

Automated ball valve vs. Automated Angle Seat Valve
We see less water hammer with angle seat valves compared to ball valves.

We also tend to see less water hammer with angle seat valves vs. a ball valve. With an angle seat valve, the linear action of the valve steam allows the valve to close in such a way so as to allow the pressure wave of the valve to dissipate past the seat and prevent shock. With a ball valve, there is no gradual break path, which means that when a ball valve closes, you can get hammer.

And because of the simplicity of design, angle seat valves are typically less expensive when compared to a 3 piece fully automated ball valve.

So it’s cheaper, more compact, easier to automate, and lasts longer than a ball valve. Why wouldn’t you want to use an angle seat valve or what considerations should you have in mind when applying them?

While Burkert angle seat valve do come fully polished, they are not self-draining. So typically we only like to use them with fluids that don’t support microbial growth. Think oils, chocolate, sanitary steam, DI water, or high acid products. For egg, dairy, or meat applications, we’re going steer you towards a fully draining valve that will clean up a little easier, like a seat valve.

Flow under the seat.

One other thing we want to consider when selecting and applying an angle seat valve is flow direction. With angle seat valves, we can have flow either under or above the seat. For gases and liquids, we use flow below or under the seat.

Flow above the seat.

For steam applications, however, we use flow above the seat so that if the actuator spring fails, the valve will stay shut. This also helps us use smaller actuators, as the line pressure helps close the valve. We need to be selective though because liquids can cause some vibration in above the seat applications.

So the next time you’re looking for a simple, sanitary on/off valve that is easy to automate and requires virtually no maintenance, consider a Burkert sanitary angle seat valve. And if you have any questions about your next sanitary valve application, contact a Triplex Sales Engineer today.

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