Direct buried cold insulated pipeline (Ammonia Export Pipeline)

[ChoiWooSeon]

Hi. Engineer guyz. Have you guyz experience about cold pipeline which is directly buried in underground ?

(1) Is it possible to be directly buried? How should we get supporting concept?
(2) Soil particle for backfilling shall be minimum sized cause avoiding impact insulation integrity.
Also, I think sand bedding should be required.

I don't have any experience about this concept. So, Please, Let me know If you got some opinion.
Please refer to below Line condition.
Fluid : NH3 Ammonia Export Pipeline (Distance 2.5KM ~ 3KM). Temperature, OPE: -33 ℃, DES: -35 ℃

 

[LittleInch]

Yes.

1) Direct burying insulated lines is feasible. All depends on what your insulation is, how it is applied and how it prevents water entering and freezing. You need enough insulation to prevent soil freezing and the issues of ground heave / frost.

2) Backfill should be relatively normal - most insulation systems have some sort of outer cover - PE pipe, steel etc. Sand might be used but often isn't required - depends on the insulation.

Minus 33C isn't too bad - Current line I'm working on is minus 168C....

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[ChoiWooSeon]

Dear LittleInch. Thank You for your reply. You were a huge help.