Boiler Flue Gas Duct Leakage Detection

can you fill it with smoke and put pressure on it,then look for leaks,or how they do it in an air conditioning unit

An infra-red camera and monitor would be another method.

I have used a government agency out of New Delhi - don't remember the name.

They come with the camera and shoot whatever you want. After review you can target your shutdown work accordingly.

Not cheap but well worthwhile. The cameras are (were) very expensive.

determine if the duct sections under review are under negative or positive pressure. Also do you suspect the leaks are under insulation?

You could try using a portable smoke (color) generator of sorts and progressivly smoke fog close to duct inspecting for smoke being drawn into duct (neg pressure) or deflected from duct (positive pressure) at leak points.

Good Luck

The infrared cameras will tell you a thousand more.

Dear Mr.brijesh ip,

You have not stated whether the duct is under Negative Pressure or Positive pressure and its level. The draft level plays a vital role in identifying the leakage. Higher the pressure diff., higher the leakage and noise level.

Obviously I presume it is under negative pressure.

Now pl. arrange to do the following.

1. Take a candle and surf the area, and if the flame is sucked that is the leakage spot.

2. Use Ultrasonic device to identify the noise level, which occurs due to leakage. Some times, the noise due to the leakage, is not audible, but Audio Detector can recognize.

3. Switch of the ID Fan and run FD Fan alone and partially make the duct to have slightly Positive Pressure and use some coloring material, to identify the leakage.

Of course we need patience to do this, and SHOULD BE ATTENDED TO, otherwise,

the Loss will be severe.

DHAYANANDHAN.S