Discuss Harley Spirit's answer to: Weld connection to oil pipe

No cause to weld pipes that small.  If you got a fuel line or oil line running less than 3,500 PSI you can use hydraulic line.  1" line is too small to weld any how.

If you think you have a crack in a gas line, here is what you have to do.

1.  Run the pig down the line to find any cracks, dips, hills, or rust holes.  The pig has an ultrasound rig on it and can spot external cracks or rust.  If you find a thin spot, then you got a hassle.

2.  When you find a rust thinout or hole, shut down the line, run a wad under dry CO2 all the way through the line, and leave the CO2 at one atmosphere.  The balloon at the end of the line has to be flat: if it pulls in, you got vacuum, if it bulges, you got pressure.  Get the pressure neutral.

3.  If you got an inside rustout, the next pig you send down has a welder on it and will push wire that is just a little softer than the pipe into the hole at about 125 amps.  Some pipes get real hard after a while.  That means they get brittle and bust.

4.  If you got an external rust out, you still gotta fill the line with CO2 but then you gotta dig to the line that might be down 20'.  The excavator operator has to be trained for it: you can't ask just any operator to dig pipes or buried power lines.

5.  Once you dig to within a foot of the pipe, you have to lower a dirt cage into the hole and put down laborers with pull-out gear and SCBA gear.  They gotta dig by hand and sample the soil to see if any fuel leaked out of the line.  If so, you got more digging ahead of you.

6.  Once you got the hole dug, and the pipe clean enough to weld, then you have to send in a pipe welder to fix the crack and he has to be in pull-out gear too. 

7.  That weld has to be inspected.  If it didn't take, EPA will condemn the whole job, you gotta send in a crew to cut out a piece from the line, weld that in place, and then inspect it again.

8.  Once it passes inspection, you gotta fill the hole with clean coarse sand, use vibrators to compact it every two feet, and once pipe is covered a foot and a half then you ca back fill the hole.  Put a tent over the hole for one last test, and then putge out the CO2 with a neoprene balloon, with natural gas pushing the balloon. 

9.  Then you can re-fill the line with whatever fuel was in it and put it back to work.

I saw jobs that had pipe lines down 3 and 4 days.  Usually we get the pipeline back up in 2-3 hours though.