Decoating of Concrete Coating on Gas Pipeline

who installed the pipeline? This could be boomtime if you do not get someone who knows what to tell you to do.

What would the cost figure be on installing an above ground temporary pipeline to carry the load while redoing the existing pipeline?

clockspring wrapped sleeve method.

http://www.netl.doe.gov/technologies/oil-gas/publications/td/psr41633%20Kick-off%20Presentation.pdf

how badly eroded are these sections? The use of brass chisels is to avoid sparks that might indginte leaking gas. At the same time you will need a lot of air to dissipate the gas, just in case. and what about catastrophic failure....explosion of the pipe from the gas pressure?

[quote]installing an above ground temporary pipeline to carry the load while redoing the existing pipeline?[/quote]

This is one of the methods used where none other will serve. The clockspring method was developed as a lower cost option. Of course, all iron/steel based pipelines fail in time and you will reach a point where a new pipeline is cheaper than the ever mounting repair cost. Oil pipelines have the same problems.

Intelligent pigging = a mechanism that is inserted into the line and runs with the fluid and examines various areas by various means.

and a cast of thousands

http://www.google.ca/search?hl=en&q=%22Intelligent+pigging+%22&btnG=Google+Search&meta=

http://www.google.ca/search?hl=en&q=%22smart+pigging+%22&btnG=Google+Search&meta=

Extremely interesting post!

Many thoughts right now, including Vibratory or Ultrasonic Bombardment.

But, not sure of the effectiveness and reality of these Techniques.

Temporary Pipeline would be safest, and this I fully recommend.

So interesting that I desire to be in the thread, with future comments emailed to me that I had to make a post.

Hello, Please check this link out http://www.pubs.asce.org/WWWdisplay.cgi?0300429 I used this technology before on a large scale and I had awesome results. This might help you. It would certainly eliminate most of the vibration on the pipeline and limit the expousure to your workers.

Thanks, Steve

You should consider using a concrete saw for this since the concrete coating has a layer of mesh which is not easy to remove with the hammer and chisel method. With a concrete saw you can set the depth of cut at a level which does not damage the pipe and you can use a water jet to keep it wet and supress sparks, although if the pipe is intact no gas should be leaking into the atmosphere.

On the other hand, if the pipe has severe metal loss, you should consider replacement of the bad sections using a hot tap and stopple method where you weld a split tee on both ends of the section to be replaced and install a bypass around it. The split tee, after doing the hot tap, will have a hinged blocking device that closes off the section to be replaced and lets you depressurize it. After the replacement is complete you remove the bypass.

Concrete can be removed with high pressure water. There are numerous companies that use extreme high pressure water to cut/remove concrete in Bridge structures. They remove the concrete with no damage to the steel, which is what you want. They also do not have ignition sources if there is a gas leak!

There may be some modification required to wrap a unit around a pipeline, but I am sure there are companies that are interested.

Eric C. Pettit, P.Eng. Senior Engineer, Community Infrastructure UMA Engineering Ltd. 200 - 415 Gorge Road East Victoria, BC V8T 2W1

" If things seem to be under control, you just aren't going fast enough. "

-- Mario Andretti --

chemical pressure bursting

chemical expansion cracking

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