So we've been doing all the paperwork required for them to move the gas line out from under that building. Naturally this is at our expense. Most of this involved getting rid of their old easement and creating a new one. We got that done last week, and today a crew of four guys showed up, with a tiny little backhoe, a larger loader/backhoe, and two trucks full of tools. They're working right now, digging trenches very carefully around the various gas, water, septic, and electrical lines buried on our property. The place where they're working is sort of a nexus for all of these, as it's right near the service entrance. Of course :)
I was curious how they'd shut off the gas so they could cut the main, which is a 2" polyethylene pipe. Turns out that's trivial: they have a clamping device that squeezes it off tight, like you might pinch a hose to shut off the flow. The polyethylene pipe is heat-welded – a very simple electric heating device heats both the male pipe end and the female fitting to the melting point, then it's shoved onto the pipe. That's it! The molten polyethylene retains enough heat to weld the two together.
|Trenching, very carefully|
|Heating a part before joining|
|Trenching the easy part|