Dear expers,

In a revambing Job, it is proposed to change the slope viseversa in the exisitng 24" flare line 18 metre long (no tappings in between and no shutdown is proposed for the line).

For the same it is proposed to lift the one end of the line by 90 mm using crane or jacks and insert sim plates below the supports to increase the elevation of the pipe viseversa.

Please tell me advisable procedure for code stress check and safe work. To counter check my analysis and report.

Regards,
Rathish.G

I would forget the calcs. You do not know what stresses are in the line now. If you like to do good job then cut the line, reposition and reweld. If the line has bowed then rotate 90 degrees.

I don't like to work on any live line. I cannot figure out if you have live or not.

Just how do you propose to change the slope of an existing line without lifting one of the pieces of terminal equipment?

If you lift the pipe only, you will have a line that has a hump in the middle and drains to both ends.

There is a very real chance that attempting to do this as you say will result in a catastrophic failure of the flare line at the jacking point. Depending on how you apply the jacking force, you could easily spear a jack through the pipe wall, buckle the pipe so it is no longer anything resembling round and hollow, or shear through the pipe wall at the edge of a saddle. None of these is terribly appetizing to me.

Just for starters, you should use a simple beam analysis, assuming an 18m straight run of pipe, and calculate the load developed at your jacking point by a 90mm deflection. You say you are going to shim this. Is your structure there capable of supporting the load you will be applying? I doubt it. So you have that to worry about, too. Then you're going to have to adjust all the other supports in the line, although they won't have significant changes in support loads.

This sounds like an idea from a #^$@! bean-counter.