Hi All,

Would really love to find an Ultrasonic tester or other method for testing the thickness of Twin Wall Pipeline. I was told that there was a $7000 unit on the market that could do it. Somehow it can recognise the outer layer as a Paint surface and measure the internal thickness.

We currently measure manually every 12 months and record cubic meters to each indiviudally marked and tagged pipeline section.... Any ideas?

drill a hole near end of pipe ur drill will only go through the outer layer of steel cause its very hard to drill through hardened layer , once u start to see the pipe leak , u know its time to change it

Drilling holes in pipe is a waste of time.With todays metals,pump volumes,mixes it's virtually impossible to say where it may fail.Even using the thickness thickness gauge is not an exact science either with twin wall pipe.The thickness gauge is usefull,however one needs to grind a shade og paint off where testing.

http://www.automation.siemens.com/w1/process-instrumentation-thickness-gauge-16582.htm

the only use full way to test twin wall with a Ultrasonic tester is by removing the painted surface on the outside of the pipe then measure its thickness,then putting the Ultrasonic tester on the inside of the pipe directly under your previous measured spot.This will give you a general idea of how much pipe life is left but only in the area you tested.Its not an exact science but Ultrasonic tester have some very good uses for judging pipe thickness

pop an elbow off and look.still the best way and while your at it rotate you pipe.

pop the elbow off and look its the best way! The thickness testers are no good for twin wall , i know it would be a heap easyer but it only takes 10mins to take off an elbow and look , piece of mind is a great thing!

Once you got the elbows off a simple check is to measure the inside diameter of the tube with a set of digital vernier gauges then compare it to a new tube.