how to measure pressure in pipe

[dgau008]

hi there,
can anyone suggest me to find correct and exact pressure in the pipe. actually i am working on the tube heat exchangers. tubes carry hot gases (burnt flue gases). i want to take reading of pressure and flow rate as well. i used manometre to measure but it increases by time becouse gases are flowing continously inside the tube. i am confused that what reading should be great.

 

[willard3]

I can't tell from what you posted what you want to know.
Why does the gas volume increase with time, for instance......

 

[zdas04]

"Correct and exact pressure in a pipe" is a really tough concept. I would assume that "exact" meant zero uncertainty to infinite decimal points. Zero uncertainty is an impossible concept, we can get uncertainty very low, but not to zero. Displayed precision is another difficulty, my 0-10,000 psig bourdon tube just doesn't go to infinite decimal places.

In practical terms, every device has an uncertainty. For example if you have a 0-100 psig digital pressure gauge with +/-0.1% uncertainty, then every reading will be +/-0.1 psig and reporting a reading of 25.1234 psig (like most gauges will) is wrong--the reading is some number between 25.0 and 25.2 psig.

Sorry, but the world we live in doesn't really support "correct and exact" it is more about "good enough".

Now if you would state your problem is engineering terms you might get decent answers.

David

 

[rmw]

Google the term: "pitot tube" or "pitot tube flowmeter" and see if that doesn't give you some answers.

rmw

 

[chicopee]

I hate it when I see a post badly written as one can only guess at the question.