Using an IR Thermal Gun to check for steam passing valves

[Aptx4869]

Greetings

I am asking about the reliability of using a thermal gun to check if there is passing downstream the valve. The fluid is either steam or air. Wouldn’t the pressure and temperature drop sharply downstream the valve if it is closed but passing ? again I am talking about air or steam. How the thermal gun can be used then ?? It is used in my plant for steam and they told me they use it for air also. I don’t know if this method is reliable or not

 

[A.T.]

Greetings

I am asking about the reliability of using a thermal gun to check if there is passing downstream the valve. The fluid is either steam or air. Wouldn’t the pressure and temperature drop sharply downstream the valve if it is closed but passing ? again I am talking about air or steam. How the thermal gun can be used then ?? It is used in my plant for steam and they told me they use it for air also. I don’t know if this method is reliable or not

Why don't you just try it out?
Look at a closed valve.
Look at a fully opened valve.
Look at a slightly opened valve.
Compare.

 

[Aptx4869]

Why don't you just try it out?
Look at a closed valve.
Look at a fully opened valve.
Look at a slightly opened valve.
Compare.

Kindly, elaborate please.

Before making comparison, someone must have something in his mind (idea).

What I understood is that I open the valve by (lets say 0.5 or 1%) and compare it with fully closed position. Do you mean if the valve is passing then fully closed and 1% opening valve will be similar to some degree ?

Also, we have some valves that are either fully closed or fully open (pneumatically actuated) and they don't have manual handle. what to do in this case ?