Problem with line size butterfly valve for throttling application

When line size butterfly valve is selected for throttling application, there will be lack of control at both low and high flow rates, which means the line size butterfly valve’s effective control range realistically occurs between 30 percent and 50 percent open.

When conditions call for the butterfly valve to operate outside of this range, it typically cycles at low flow and is sluggish at high flow. In these cases, the valve is often switched from AUTO mode to MANUAL, or it is severely detuned. Which means it provides no control at all

Now there is an answer to this control range dilemma: the Fisher Control-Disk.

The Control-Disk valve stretches the control range to begin at 10 percent open and extends the range to 70 percent travel. That’s a 300 percent increase in application coverage!

Watch the animation by clicking the picture below.