Cold Cut of Existing Buried Gas Line
Cold Cut of Existing Buried Gas Line
(OP)
We are going to install a 56"x42" barred tee on an existing gas line. I am wondering, from experience point of view, how much ovality can we expect, on the buried 56" line, when it is unearthed. The thickness of CS line is estimated to be about 0.78" and approximately one meter soil is covering the pipeline.
If it is considerably high, what's your suggestion for fabrication/erection of barred tee.
Thanks in advance.
If it is considerably high, what's your suggestion for fabrication/erection of barred tee.
Thanks in advance.





RE: Cold Cut of Existing Buried Gas Line
weld pups on the tee. take along some extra pipe joints.
if ovality is too much, cut pipe in a different place.
Learn from the mistakes of others. You don't have time to make them all yourself.
RE: Cold Cut of Existing Buried Gas Line
http://www.youtube.com/watch?v=lEukhxdzz4E
RE: Cold Cut of Existing Buried Gas Line
Ovality is not the most huge problem, I'm usually more concerned with getting the two ends to match the fitting (watch the video, the pipe is always in some amount of a bind and it will move).
BigInch's advice addresses this in the only way I've ever found that works. Pipe above 20" I like to put a full joint on both sides of the tee. Requires a big hole, but it lets you address ovality and pipe jumping issues.
David Simpson, PE
MuleShoe Engineering
Law is the common force organized to act as an obstacle of injustice Frédéric Bastiat
RE: Cold Cut of Existing Buried Gas Line
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way
RE: Cold Cut of Existing Buried Gas Line
Learn from the mistakes of others. You don't have time to make them all yourself.
RE: Cold Cut of Existing Buried Gas Line
What about using Tirfors to achieve alignment, instead of extra pub?
RE: Cold Cut of Existing Buried Gas Line
You can use all sorts of devices to achieve alignment - digger buckets, cranes, tirfors etc. The key is to have as long a section of pipe (15m at least) able to flex as you can or else you're welding in a high level of bending stress.... The extra pup is for when you check the location of your tee and discover laminations, excess ovality (which was your original question), reduced wall thickness etc etc but can't move your tee location very much or at all.
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way
RE: Cold Cut of Existing Buried Gas Line
Either way.
Learn from the mistakes of others. You don't have time to make them all yourself.