Linear and equal percent characteric of control valve

The question is hard or impossible to answer. If you describe an application, then someone may make an argument that you should linearly control a valve, and others may argue that you should control it logarithmically, exponentially, or as a percentage of total flow, or some other way. Pressure doesn't have much to do with a valve transfer function that's non-linear, unless you have a really weird fluid.

Hi there,

You need to know your process characteristic to determine the control valve characteristic.

It is impossible to give you answers without this.

Generally speaking you would use a linear valve for controlling flow, a equal percentage for controlling a level/pressure. This is only a guidline as you really need to know your process characteristic to select the correct control valve characteristic as sometimes the process would have a different characteristic.

Get the book refered to in the previous link - it might give you a better idea.

Regards,

Craig