In many engineering projects, control valve problems are not caused by poor product quality,
but by incorrect valve sizing during the design stage.
One key principle is often overlooked:
At minimum, normal, and maximum flow conditions, the valve travel should remain within 20–80% of full opening.
Why does this matter?
--Best control accuracy
Control valves achieve the most stable and responsive flow control within the 20–80% travel range.
--Reduced vibration, noise, and wear
Operating near the fully closed position (<20%) may lead to instability and valve hunting,
operating near the fully open position (>80%) leaves little room for effective control.
--Sufficient operating margin
This range provides flexibility for process variations and future capacity changes.
Good valve selection is not about “can it work,” but about “can it control well.”
If your control valve is constantly operating at 10% or 90% open,
the root cause is often valve sizing — not the valve itself.
