1 reply to this topic

[ozgur]

Dear All,

Nowadays, I am working on liquid and vapor pipelines which tranfers LPG from a LPG storage facility to another. Length of these pipelines are about 7000 m.

As I found in the literature and in my sample projects, normally lpg tranfer lines are not insulated. Only the suction lines of pumps are insulated to minimize the risk of vapor formation in the pump inlet.

But our project will be implemented on a very hot area in which max shade temperatures are about 55 C. So i am worried that such a long pipe will take too much heat through solar radiation without any insulation which will may cause vaporation due to temperate rise on LPG.

Is there anyone who has experience on this issue and willing to share his/her experience with us?

Best regards...

[ankur2061]

ozgur,

Long-distance (your distance is 7 km) hydrocarbon pipelines are normally run buried for the very reason that above-ground pipelines can see an extreme change in ambient temperature in areas where summer / winter or day / night temperatures can have extreme variations, thereby effecting the hydraulic efficiency of the pipeline. The hydraulic eficiency of a pipeline can be affected by a change in fluid properties such as density and viscosity of the fluids due to major variations in the ambient temperature. As an extreme, above ground piplines can face partial vaporization (for liquid lines) due to high ambient temperatures and freezing or formation of ice /hydrates due to low ambient temperatures.

A disadvantage of running long insulated above ground piplines is the deterioration of the insulation over a period of time due to water / mositure ingress for the commonly used insulation materials.

Even if you decide to provide an expensive water-proof insulation material, you need to justify the economics for that vis-a-vis running the pipeline buried. Practical experience says that it would be more economical to run the pipeline buried than running above ground with insulation and sleeper supports over long distances. This is specifically true for large sized piplines such as 8 inch and above.

Hope this helps.

Regards,
Ankur.