#459 Valve vs Damper: New Damper Definition Proposal

Keith D Bishop Mon 19 Dec 2016

It was brought to my attention this morning that there is a significant discrepancy in how we handle a valve tag as opposed to a damper tag. In actual operation, there is very little difference in how valves and dampers are used. The fluid involved simply changes between the two. (I understand there are air valves, but those are not generally encountered.)

Let’s start by looking at our two current definitions of these tags:

  • damper: Damper position measured from 0% (fully closed) to 100% (fully open).
  • valve: Marker tag on point which indicates a valve used to regulate or control the flow or pressure of a fluid. It is used with cmd to indicate the valve command: true/false (open/close) or 0% to 100%. It may also be used with sensor to indicate a feedback sensor such as a voltage giving exact position between 0% and 100%.

Why aren’t these two definitions more similar? Why does damper suggest a numerical value while valve does not make this assumption? Can a damper not be two-position and be stored in a Boolean value?

To correct these discrepancies, I propose that we modify the definition of damper to read:

“Marker tag on point which indicates a damper used to regulate or control the flow or pressure of air. It is used with cmd to indicate the damper command: true/false (open/close) or 0% to 100%. It may also be used with sensor to indicate a feedback sensor such as a voltage giving exact position between 0% and 100% or open/close as indicated by end-switches.”

Leroy Simms Tue 20 Dec 2016

I second that change.

Brian Frank Tue 20 Dec 2016

Seems like much more thorough language than the original definition. I pushed that change

Zachary Danyluk Fri 7 Apr

Yes, this makes sense to me also. One other thing that I have always done to indicate the difference between a analogue command and a binary command (2 position damper/valve vrs a positional damper valve) was that a command was the binary value, and a output was a positional value. That was just a rule of thumb, but some kind of indicator would be nice. I found it speeds things up.

Login or Signup to reply.