The Chopper Compendium

This shows the spray can and the brush. I usually just spray some pt into the cap and dip the brush in it.
This red spot is pinhole porosity. Very minor, but it will be repaired. There is another on the end of the tee. These are both located where the run-off tab was removed and the area smoothed.
This is an example of the capillary action of the PT, and a non-relevant indication. The vertical dark red stripes are at the backing strip used behind the horizontal weld. This area will be welded tomorrow.

The girth welds will get MT inspection, but there is mandatory 12 hour wait time before doing am official inspection. We'll do a PT for info only, in case there are repairs, so the welding crew won't have to wait.
The MT can be fluorescent or black on white, both are called "wet mag". The fluorescent is difficult because you have to have a light tight cover and use a black light. I expect to do the black on white method.
I'll get some pix of that procedure also.

Speaking of procedures, these inspections are done following written procedures that have been submitted to the client and gone thru their approval process. Technicians using the procedures take exams on general knowledge, interpretation of code, and a practical exam on items with known discontinuities and/or indications before being certified.

More in a day or so...

I'll post a few pix of the welding activity on the girth weld. This is a fillet weld joining a 48"x48" split tee to a 48" pipeline while crude oil is flowing.
The oil is about 55F, so it removes heat from the operation continually. To mitigate that, Miller inductive heating is utilized, using tubes wrapped around the circumference, and placed within a few inches of the weld area. This falls under DOT regulation, so the Welding Engineers require continuous inspection while welding. The welding procedure calls for using 4 welders, one on each quadrant. The minimum preheat on the pipe is 86F and on the Tee is 150F, and 8018 electrodes.
The WPS has ranges allowed for essential variables, the most important being electrode diameter, volts, amps, travel speed and heat input.
The inspectors are required to observe the entire process and document significant readings and changes, and approval or rejection.

There's a lot more to it, but thats a pretty good intro.
This shows one welder working on the upper quadrant. Below his elbow is a flat board with fire balnket. Its attached to the pipe with magnets and keeps the lower welder from getting fried. In the center is the vertical weld, with the Miller heat wrapped around the pipe.
This shows both welders on one side of the pipe
You can see all 4 welders in this one. It's pretty cool to see these guys work together. All professional, no drama, easy going.
Fitter running 9" wire wheel after each pass. Another fitter on the other side. These guys are kept busy adjusting amps and handing rod to the welder, cleaning all the time.

After the weld is visually accepted, a 12 hour delay is required before MT NDE inspection can be done.
This project requires either fluorescent or black on white "wet" mag (mag is short for Magnetic Particle).
Fluorescent can be a real pain, you obviously need darkness, so you have to use a cover to keep ambient light out, use a blacklight which has to warm up, and is very sensitive to knocks. We used black on white, which is done in white light, ambient or artificial, with a minimum of 100 foot candles of brightness.
Black on white refers to the white paint sprayed onto the weld, and another substance sprayed over the dry white paint. The second spray has black particles suspended in a oil-based solution. An inspection tool called a contour probe is used to apply a magnetic field into the weld and base metal, and while the field is in the metal, the black spray is applied. Any indications appear as a black line that shows up against the white contrasting background color.
This shows the weld after applying the white contrast paint.


Close up of the white on weld


Clear shot of the probe in place


This is the probe holding the field and black spray applied. Had a hard time showing the black spray on the weld, but you can see the white paint thru it, and the black tends to follow the valleys between the passes, and gathers at anomalies in the cover pass, like starts and stops, undercut between passes, etc. The spray is applied between the legs of the probe fairly heavy, but too much is not good, it might mask an indication.
Almost forgot, the magnetic field is induced twice for each area, the second time at right angle to the previous time. An indication might not be revealed in one direction, but could show up in the second test, due to orientation in the metal of the inclusion and the magnetic flux field.



The contour probe has adjustable legs that bend and can be spread to whatever width you need to fit an item.
This one is a DA-400 and can use DC or AC. Each is better suited for different applications, but DC is known to penetrate deeper and can find indications or inclusions as deep as 0.050" deep. Technicians have to be tested before being certified to operate them.

Holy Diaphrams Batman! That's an awesome, uhh..., expose'.
Thanks for all that.
And I thought you moved up there just to get away from it all.

Perhaps, I'll post pics of my progress (or lack or it, unfortunately) when I'm free tonight.

Sorry for jacking the thread, just seemed like a good spot to show one of the methods in case someone did a search.

We use that stuff at work to check for breaks in the die cast machine tie bars as the lock up over 900 tons and cracks are detremental to their operation.

It is easy to use.

It allows use to plan for changing them.

Sure, there are lots of applications for this, and a 10 minute description would pretty much cover all you need to know, maybe even 5 minutes.

The Alaska Pipeline gets a LOT of scrutiny from gov agencies.
DOT, BLM, EPA for the Feds, DEC and others for the State.
Alyeska spends a lot of time and money complying with all the regulations.
The reports are in depth, and triple checked for accuracy
Every inspector has to be tested and only certified after passing and being approved.
Every inspection we do has a report, and the reports on all parts of a project are collated into a final report.

On a different note, IT RAINED TODAY ON THE NORTH SLOPE. Then it blew, and the wind polished everything into
slippery snot. My coworker stopped at the security guard shack, and slid sideways. Since he isn't very experienced
on icy roads, I offered to drive. When I got out, yep, right on my ass big time.
While this is very unusual, it has happened before.