Specialist for Ethylene Pipeline

[peedco]

Recently I have started my new job in the world most longest ETHYLENE PIPELINE Project. Since the geographical and topographical characteristic and climatic conditions at different segment of right of way of the pipeline is different from each other, it has made is as the most complicated one in operation point of view.
Ethylene is compressed supercritical gas in summer conditions, when it passes the pipeline located in mountainous area and it is compressed supercritical liquid in winter conditions, when it passes same rout. So it is completely different, comparing to the natural gas pipeline.
For this reason I am wondered which type of machines (compressors or pumps) we should select for transferring of ethylene, to provide required head and maintain the pressure of the ethylene at the required level at different section of the pipeline.
If any one who has experience in Ethylene pipeline please help me to find:
*)Which criteria I should consider for selection of the right machines (compressors or pumps) for transferring ethylene?
*)Which skills we should consider in design of pipeline to minimize risk of two phase flow in abnormal operating conditions?
*) Do we need pig launcher and receivers for pipeline what should be the pigging procedure?
*) What safety factor we should consider for Right Of Way regarding the supercritical conditions of ethylene which is different from natural gas.

 

[narenr]

You will need to do hydraulic analysis for flow assurance to determine the flow regime. Pipeline elevation and insulation data is very critical if the pipeline is long. If you have rapid decents (steep long downhills) there can be surge effects which needs to be addressed in the mechanical design. The flow regime determines the pigging requirement and frequency. Refer applicable [country specific or local requirements or follow ISO 13623 to start with] pipeline code for the FOS which depends on location apart from fluid category.

Narendranath R
Pipeline engineering is made easy with state of the art computer software, visit

http://www.narendranath.itgo.com.

 

[peedco]

This Pipeline (WEP) is the longest ethylene pipeline in the world. Length of WEP is about 2300 Km and capacity of transferring is 3.5 Million Ton per Year for feeding 11 Petrochemical plant. This pipeline feed from 2 Olefin plants from Assaluyeh & Gachsaran in south of Iran. Pipeline was designed to transfer supercritical ethylene. Operating pressure is 60 ~ 93 Bara and eight (8) compressor stations are considered to compensate frictional & static pressure drop of pipeline. Productions of polymer in pipeline increase the roughness of pipeline and there are comments that Pipeline shall be pigged for increasing capacity of pipeline (Reference: Polymer cleaning of Wilton-Grangemouth Ethylene Pipeline – 1997). We assumed that Compressor stations consist of Variable speed Electro-centrifugal compressors. Electro-compressor can be operate in
50 ~ 105 % of design RPM.
Elevation change in pipeline is about 2700 m and some of compressor stations located for compensate static pressure loss of pipeline in winter (dense-phase of ethylene).
Anybody knows information about these procedures for ethylene pipeline:
1- Safety area around the pipeline (Area of Right of Way)
2- Purging of pipeline (limitation of water & oxygen content in ethylene pipeline before startup)
3- Pre-commissioning & startup
4- Pigging procedure