Safety Distance between New LPG Pipeline to Exsiting Hydrocarbon pipe lines in the Existing Pipeline

[antojerald]

HI all,

Could any body clarify me the following?

We are doing a tecno economical study on the LPG pipeline which has to be layed for abt 230 Kms.

We are planning to use the Existing pipeline corridor, But the issue is could you please tell me the Minimum safety distance to be followed for the LPG pipeline from Existing Hydrocarbon liquid Pipelines.

please provide me the reference also.

Thanks,

Anto

 

[DekDee]

" INCOMING" !!!!

 

[LittleInch]

Unless there is a limit in legislation in wherever your pipeline is, there is no specified "safety distance" for an LPG pipeline to another - I assume it is in liquid phase - AFAIK.

The separation distance then mainly is about a practical limit in terms of installing another pipeline next/over what I assume is a working pipeline. I would recommend at least 1m separation edge to edge, but in theory could be a minimum of 300mm. Of course the existing pipeline owners will have their own thoughts and rights over the strip the existing pipeline is buried in so they're you're first port of call.

My motto: Learn something new every day

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

 

[bimr]

It will also depend on the soil mechanics, the diameter of the pipe, and the pipe depth. All of these factors are unknown at this point. Another issue that should be reviewed is if it is possible to drive over the pipelines as parallel pipes may have an affect on each other.

Practically, if the trench is excavated in poor soil, a good practice is to place good embedment to a width of half a pipe
diameter on each side of the pipe. So the minimum trench width is sometimes specified to be two pipe diameters in poor
native soil with low-bearing capacity.

You would want the new pipeline excavation to avoid having an affect on the existing pipe installation. Without knowing more details on the installation, a number for planning purposes that I would recommend is 2 meter separation between the width of the pipe trenches.

Here is a publication to get your started.

http://www.steeltank.com/Portals/0/pubs/Welded Steel Pipe 10.10.07.pdf

 

[LittleInch]

If you go for 5 m separation you won't be too far away from reality which takes account of most of the issues discussed so far. There is nothing especially hazardous about LPG compared to high pressure / large diam gas which can create a large crater which can have an impact (literally) on parallel lines. Even if the LPG catches fire it won't harm another buried line at that sort of distance (5m).

My motto: Learn something new every day

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

 

[BigInch]

The major issue is to consider that there are many interests in securing RoW for LNG pipelines, not all of them logical, or based on facts. The possibility of a large explosion of another nearby high pressure pipeline, or rupture and washout of another, leaving a crater of 4 m diameter or so, plus another safety distance of 5 meters or so, will often put you away from the nearest pipeline by 10 m or more. It's perception that matters, nothing else, and 10 meters seems to satisfy a lot of people's perception. Not much to go by in the way of codes or recommended practice, except the blasting distance provisions of AGA "Pipeline Response to Buried Explosive Detonations". How many kilotons is the next pipeline worth???

I hate Windowz 8!!!!

 

[ripaldee]

Consider too the access for construction or maintenance equipment between the proposed LPG pipeline and the existing HC pipeline. As a safety precaution, excavate away from the existing pipeline.

 

[weldstan]

All too many disasters occur when excavating near operating pipelines. Be very aware!!!!