UT Weld Testing on Pipe

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I live in North Carolina, I work for a Mechanical Contractor- we do alot of pipe welding. We were recently on a job at a local state university when the engineer ordered some of our welds to be ultrasonic tested.......this is the first time in 16 years this has ever happened to me. We were concerned that some of the welds would fail because we did not have sufficient penetration ( the pipe was butted together with no gap in betweeen) but all the welds that were tested passed. Some of the welds that were tested ( 2.5" - 6") had full penetration, some did not. This ultrasonic testing method is not as bad as I thought.Last edited by 1lowandslowbusa; 12-20-2009 at 12:31 PM.
Reply:This is what Welding Procedures are for.
Reply:how thick was the pipe?
Reply:The pipe was sch.40 around 1/4" wall thickness
Reply:Ultrasonic testing reliability is highly dependant on the individual operating the machine.  It’s very easy to miss things with UT because of discontinuity orientation to the sound path, improper calibration to name a couple.  But properly done it will it will find some really small stuff.I would be curious to know the code/acceptance criteria these welds were weld to.
Reply:Well....I once passed UT on 6" sch 40( It might have been 4") by welding the open root DOWNHILL with 1/16 dual shield. Then another downhill pass to build it up a bit. All this was fixed pos in 6g and 5g. I think there were 2g ones that did open root with 1/16 dual shield too.  I swear on my life I would not have done it if the foreman hadnt threatened to fire me if I didnt. I quit a week later after I found another job. No kid to feed I would have walked that instant. This was on the water distribution manifold of a waterbody for a mining dump truck.it didnt threaten anyone life just my former employers reputation lol. Moral of the story Ive seen some janked up **** pass UT.