The Sanitary Butterfly Valve controls flow by rotating its disc, while the Sanitary Ball Valve uses a rotating sphere with a hole in the middle.
While both valves looks similar, here are some of the most important distinctions.
The pressure ratings for Dairy Ball Valves are many times higher than Dairy Butterfly Valves. A 1" Butterfly Valve can handle 140 psi while the 1" Ball Valve can take 1000 psi. This is why we often see ball valves used at the bottom of large tanks, they are simply much stronger.
There will be slight flow pressure drops in Butterfly valves because its disc is always in the way of the product, regardless being fully open or closed. A ball valve on the other hand, when fully open does not obstruct flow in any way.
Sanitary Butterfly valves require gasket replacements after considerable use. The ball valve parts are much more durable and can achieve perfect shut off even after years of use, without replacing parts.
Sanitary Ball valves can be equipped with most commercial actuators due to its stainless steel mount. Butterfly Valves usually require manufacturer specific actuators due to different body designs.
So far its not looking good for the butterfly valve. But the biggest advantage of the butterfly valve is price. Ball valves cost more then butterfly valve because of more complex construction. Larger ball valves usually cost a few times more than their butterfly counterparts.
So there you have it, the most import differences between the two valves.
NKE Flow is a supplier of sanitary valves. We carry Sanitary Ball Valves and Butterfly Valves. For more specifications for the two valves, explore the links below.