Gas Pipeline

Dear Krishnan,

Water inside a gas pipeline in operation causes a number of problems (internal corrosion).

You can check in Google full info...

For example:

http://www.ceps-as.cz/suseni-en.html

B.R.

Gas and water under pressure can form clathrates, or hydrates.

http://en.wikipedia.org/wiki/Clathrate

these are solids and an accumulate and block pipes, and break compressors etc

Hi Krishnan,

You require a dry gas so that during rapid decompression and subsequent cooling(Jule-Kelvin effect, adiabatic expansion) the line will not become blocked due to the formation of ICE.

Hope this helps.

To achieve a dry pipeline it has to be correctly precommisioned by pigging or vacuum drying. Any gas introduced into the pipe has to be up to spec regarding its dryness.

from a corrosion point of view is necessary to avoid internal corrosion. if you can dry the gas to achieve a dew point lower enough to avoid any condensation then you can consider you gas as non-corrosive.

This is taken from the Norsok M-001 Material Selection for Oil&Gas.

"A gas is considered dry when the water dew point at the actual pressure is at least 10 °C lower than the actual operation temperature for the system."

" For pipelines with dry gas or non-corrosive fluids, no corrosion allowance is required."

hope this help

V.

gas hydrate plugs show up as a pipeline problem that must be guarded against

http://www.google.ca/search?hl=en&q=%22gas+hydrate+plug%22&btnG=Search&meta=