Looks at start date, only took 12 years!
Just kidding! That's interesting and informative, thank you
I have a very particular knowledge base, it never Normally comes in useful on these forms or outside of work.....
If you guys need knowledge in the following;
* Steel making
* Control and instrumentation systems
* HV AC or DC systems
* Industrial pipelines both gas or oil
* Industrial ups
Anything else you might as well ask a tree outside
Oh and if anyone is worried about pipelines in the UK, we are governed by the HSE under PSSR;
Maximum is 12 years between pigging and all cp systems must be able to be monitored remotely.
The years between runs can only be reduced not increased, reductions are based on age, quality of materials, depth of pipeline and previous results. Some of the older pipelines need to be pigged every 3 years as the welds are not to code, they aren't buried deep and they have non standard materials, so most defects require digging up, shelling and sealing.
A pig run usually involves the following:
* Cleaning pig, it's basically a series of wire brushes and strong magnets and two rubber seals that scrape the inside of the pipeline and carry the crap to the pigtrap where it can be removed.
* Gauge pig, litterally is a disc of aluminium plate, it has been cut into sections, its whole point is to show deflections inside the pipeline, these deflections could be dents, weld or not fully opened valves. The gauges main job is to protect the intelligent pig.
* Intelligent pig; this is the expensive boy. Most companies rent this unit rather than buy one. It measures the thickness of the pipeline using x-ray radiation and can also measure for lateral strains on the pipeline. It's also one of the few that can control it's own speed and has a tracker that can record location of issues.
Pigs can go from 6inch 10kg units to 48 inch 6 tons behemoths.
After a defect has been found HSE give a maximum of 12 months to dig down to it, this can be reduced depending on severity of the issue.
