Allowable pipe stress

[rob_quan]

I'm to prepare a pipe lowering procedure for a 120m long pipe section. i've however hit a snag with the lowering calculation(allowable pipe stresses to be considered) and the lift point spacing. I'm in this situation cos i've always lowered shorter pipe sections and without any written procedure in place. Any help?

Pipe Sch used is 80
Length of pipe is approx. 12
Pipe size is 12inches

 

[MFJewell]

Model it as a beam with simple supports at the lift points. You can calculate deflection of the span, moments, and stresses.

 

[LittleInch]

Are you trying to lower this in as one lift for the entire 120m in one go or install it like a pipeline?

How many cranes / sidebooms?

What sort of "snag" have you hit?

A welded 12" schd 80 pipe should be good for lift spacing at 15 to 20m. Once off the ground though it will act like a piece of well cooked spaghetti.

The hard part is actually co-ordinating the lifting machines over that sort of distance.

It all needs to rest on the head of the lowering in foreman / supervisor.

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