LPG pipeline commissioning procedure

[Esoufi]

Help me to find a procedure for offers LPG pipeline commissioning about what is the ideal LPG pressure to move the train pigs/Nitrogen column, how to operate to fill the entire pipe (100 Km) with LPG liquid phase

Thank you in advance.

 

[LittleInch]

In essence quite straightforward. You will have a minimum pressure that you need to maintain to keep the LPG at to keep it in a liquid state at your design temperature. You pressurise the pipeline with Nitrogen ( a lot of nitrogen, but that can't be avoided) to above that minimum pressure, then insert a pig (bi-di) and start pumping at a rate equivalent to betwenn 1 and 2 metres /second. Release Nitrogen at the other end maintaining your minimum pressure. You need to look at the profile so that the minimum pressure is maintained at the high points which may be higher than in normal operation and you may need to increase Nitrogen pressure if there is a long downhill slope. Make sure the vent can handle some bypass LPG or route it via a tank which can release the volume of Nitorgen that is required.

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way