How would you?

Mar 22, 2010 23 Replies

I agree with JTMcC, but wish to add that (at least here north of 49) fill and cap procedures are usually location dependant. Outside the fence, downhill and xx10 is normal but inside the fence most work is uphill with xx18.

Outside the fence speed is king, and downhill allows the use of higher current and larger rods for high deposition rates. In addition, the pipe is normally buried which gives it added support and much more constant operating temperature. The consequence of failure can be lower.

Inside the fence the pipe is usually above ground and subject to much more variation in operating (and ambient)temperature and pressures. IIRC the codes are also different, and the consequence of failure can be higher.

For non code work such as water system piping, procedures are often not specified and the weldor can use their own discretion and experience. Small dia. propane and natural gas systems were commonly done with OA, but most are now plastic.

JMHE &.02

I already have : ) Right now most of it's going to refineries in the midwest via the Keystone, the two spreads going into Oklahoma haven't been laid yet but should be soon. The Keystone XL will run down to the gulf coast over the next two years.

The pipe mills have been going full tilt for several years now. I know a lot of big projects have bought line pipe from sources they would rather avoid but have no choice. They are having to put in pipe orders several years ahead of construction. Good times for the pipe mills tho!

There have been quite a few failures under hydro of X-70 spiral line pipe out of China the last couple of years.

JTMcC.

snip

While we all need to be mindful of consequence, there is often a much greater QC focus on the welds & weldors than on the pipe itself.

I worked on a huge oil sands upgrader project that was built using very large prefabed modular pipe racks. After the modules were placed and connected, the piping was pressure tested which resulted in several weldors being skidded due to failures and leaks adjacent to their welds. When the repairs also leaked, somebody thought to test the (offshore produced, Romanian?) pipe which resulted in the replacement of something like 25 miles of defective porous pipe, some as large as 48". Lots of work for cranes and weldors/pipefitters to remove and replace (and reinsulate) the pipe from the large multi level racks.

I understand some of our upgraded bitumen is going to Oklahoma for refining, you may see some of the pipeline work.

Worksafe.

The materials used in Power/Process piping almost always have

I should of mentioned high temperature service in addition to corrosion resistance. The operating temperatures in Power/Process piping are commonly much higher than in natural gas/products cross country transmission piping. And that puts another set of demands on the parent material and thus the consumables used.

JTMcC.

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