[ce4]

The compressor stations are alongside the gas pipeline network. These put in the energy needed to keep the gas flowing over long distances through the network.

Without those it would be just like a very very long garden watering hose that has a trickle of flow compared to a short one.

[londons_explore]

I don't believe this to be the case.

The differential pressure from one end of a gas pipeline to the other is not 1800 psi - it is more like 20 psi. You don't repeatedly recompress along the pipeline length - you compress once at the start, and decompress once at the end.

The reason to use high pressures is because for a given pipe diameter (and therefore cost), you get far more gas transported at high pressures than you do at low pressures.

[formerly_proven]

Most of the energy in pipelines is lost through friction inside the medium and friction between the medium and the inner wall. These are very much not reversible processes. Also the pressure differential is much bigger than you suggest. E.g. the pressure differential across NS1 was nominally around 110 bar (1600 psi) with an inlet pressure of 220 bar (3200 psi) and an outlet pressure of half that.

> You don't repeatedly recompress along the pipeline length - you compress once at the start, and decompress once at the end.

There are often recompression stations in pipelines precisely because pressure drops across the length, and on land it's cheaper to have those along the length of the pipeline than one really big one like NS1 had.

[sveng]

Interstate or longer intrastate pipelines require compressor stations every 75-100 miles. The parent article mentions this under "Compressors". As another comment states, friction is the main reason.

[djaychela]

It also means large storage tanks (known as gasometers in the UK) aren't needed. A couple of hundred meters of pipe at high pressure holds the same amount of gas as one of them.

[w1]

>> You don't repeatedly recompress along the pipeline length

Yes, you do. That is the primary purpose of transmission compressor stations. You may just lose a few psi per mile or something, but over the course of 100s of miles..

[tomas789]

I don’t think that is the case. Surface roughness and directional changes are big losses. For example a single valve on a high pressure line can have a bigger pressure drop than 2 bars. So 160 km of a pipeline will drop a lot more.

[tantalor]

Companies construct these stations along natural gas pipelines and use them to compress gas so it can continue flowing downstream to its final destination