Chris,
The Pipeline Rules of Thumb Handbook, Gulf Publishing Company, Houston, TX has a section that addresses stress calculations for cold bends and would be a valuable addition to your reference library.
It also contains a section on strain calculations for laying pipelines in a curved...
Ivu,
It depends upon what you are trying to protect the pipline from. The two biggest causes of pipeline leaks (according to USDOT statistics among others) are corrosion and outside (3rd party) damage.
As for corrosion mitigation the biggest factor is the integrity of the pipeline coating...
Butelja answered the question well as to the function of the vent pipes and casing pipe, however here is a minor correction:
The casing pipe is not seal welded to the carrier pipes. Indeed every effort is made to keep the two electrically isolated to avoid interference or conduction of...
