I need a theoretical background on pressure analysis to detect leaks in pipelines.?

Answer 1

To prevent the leakages , you have to select the suitable MOC of piping with respect to nature of fluid (acidic,basic,...),temperature,vacuume,pressure,etc..
So, for high pressure ,you have to select the schedules of pipe .
as the schedules of pipe increases , the pressure withstanding capacity will be increases.Also , its thickness increases.out side diameter will remains same.

So, what is your exact question regarding pressure analysis,I couldn,t understand.
If you want to understand the pressure,pl. click on:
http://en.wikipedia.org/wiki/Pressure

(As an example of varying pressures, a finger can be pressed against a wall without making any lasting impression; however, the same finger pushing a thumbtack can easily damage the wall. Although the force applied to the surface is the same, the thumbtack applies more pressure because the point concentrates that force into a smaller area. Pressure is transmitted to solid boundaries or across arbitrary sections of fluid normal to these boundaries or sections at every point. Unlike stress, pressure is defined as a scalar quantity.

The gradient of pressure is called the force density.

For gases, pressure is sometimes measured not as an absolute pressure, but relative to atmospheric pressure; such measurements are called gauge pressure (also often spelled gage pressure). An example of this is the air pressure in an automobile tire, which might be said to be "220 kPa", but is actually 220 kPa above atmospheric pressure. Since atmospheric pressure at sea level is about 100 kPa, the absolute pressure in the tire is therefore about 320 kPa. In technical work, this is written "a gauge pressure of 220 kPa". Where space is limited, such as on pressure gauges, name plates, graph labels, and table headings, the use of a modifier in parentheses, such as "kPa (gauge)" or "kPa (absolute)", is permitted. In non-SI technical work, a gauge pressure is sometimes written as "32 psig", though the other methods explained above that avoid attaching characters to the unit of pressure are preferred.)

For leak test checking in pipe line,the pressure test should be taken at 1.5 times its working pressure.
You can take hydrotest or pneumatic test .
But in my opinion , pneumatic test is far better.
For that you should use instrument air or nitrogen.

There are more non-conventional testings like-[NDT]-microstructure analysis,PMI test,DP test etc.
If microstructure is deteriorated, then you should go for replacement of pipings.

Answer 2

You must be refferring to gas pipe lines right? Other wise you would see where the leak is at unless the pipe is miles long like in some cases. You should be able to, by all the numbers that you have, be able to see how much you get, how much you give and tell if there is in fact any missing which would indicate a leak. You really shouldn't need any theoretical background on pressure.

Answer 3

See Technical Review of Leak Detection Technology - Crude Oil Transmission Lines 3.2.2 Pressure Analysis (Rarefaction Wave Monitoring) http://www.dec.state.ak.us/spar/ipp/docs/ldetect1.pdf