SharkTail CONTROL CARTRIDGE

The SharkTail is the second patented invention in Yeary Controls current line-up of Control Cartridges, and Devices. It is our simplest and least expensive control valve offering. The SharkTail insert corrects the instability and poor control that is experienced during the first 25 t0 30 degrees of disc travel when throttling flow through triple eccentric, and double off-set butterfly valves. Through a company sponsored research program at the University of Illinois, we discovered that the root cause for this inability to effectively control flow with these styles of butterfly valves.

 

THE CAUSE FOR POOR CONTROL

The flow on one side of the disc cannot be modulated effectively because the butterfly valve's disc edge immediately distances itself from the valve body wall.

 

THE PATH TO  EXCELLENT FLOW CONTROL

In order to generate an equal percentage flow characteristic only one side of the valve's body seat  and one of its disc edges is needed to throttle the flow . So, by allowing flow through just one side of the buttefly valve's disc, and restricting flow through the other side, it is possible to get both an equal percentage flow characteristic, and much more stable operation resulting in the kind of predictable control, that is typical of segmented ball style control valves.