Industrial Radiography

If you use source radiograph for only 15mm thickness plate, Im afraid you cannt get any information but a black on film. if double walls work, will 30mm. I guess youi use this method for inspection.

Have you tried UT? A scan can do the trick, I think. you can use either direct probe or angle prob.

the reflect wave has different from whole lining and lack of lining parts. then you can locate the fault spot.

or use x-ray in place of r source. doulb wall radiography, try 260kv 5min expose, may get a relative clear image. although has out focus.

the foolish job is use a crawler with a camera inside the pipe. as it has large diameter up to 1.5M.

if you have a infrared camera, you can also try this method. warm the pipe and then inspect with the thermograph image. my client had used this method for inspecting firebrick lining .

Did you try a stethoscope to listen to the turbulence/ cavitation likely?

This one has an software package for visualizing what you pick up.

STETHOSCOPE

Milo

I agree with the other contributors, radiography is not the way to do this - both UT and Thermography can be very effective in locating such areas - well so we have found.

What diameter is the pipe and the run lengths involved?

I'd consider using a video camera on a crawler, as long as the pipe invert is passable. These crawlers can measure how far into the pipe they are, so anything inside can be located. This method is commonly used to inspect storm and regular sewers. You can also check with pipeline rehabilitation companies.

You may want to try a ultrasonic inspection from the inside. Below is a link to a company that puts a ultrasonic recorder into a active water main. We are considering it, but have not used it, so I can't speak to it's actual effectiveness - but it may do what you are after.

www.puretechnologiesltd.com