FACTBOX: Europe's Russian gas watchers

(Reuters) - European gas consuming countries have dispatched a team of experts to Russia and the Ukraine to monitor gas flows from Russia to Europe.

The monitors reported on Thursday that no gas at all was flowing across Ukraine, meaning about 20 percent of Europe's supplies remained cut off.

Following are some details of what the monitors are doing, what technical gas is and the arguments put forward by the parties involved.

WHO IS MONITORING WHAT?

There are 19 gas experts from all of Europe's biggest gas companies monitoring gas flows at five pumping stations and control centers in Russia and five in the Ukraine.

The European Commission has also sent four gas network experts from the EC's Directorate-General Energy and Transport to monitor flows.

The 23-strong monitoring team is being rotated, with four members of the current team due to return to Europe shortly to be replaced by other industry representatives.

Companies in the current mission apart include Germany's E.ON-Ruhrgas, RWE, GDF Suez and ENI, included Slovakian SPP which is run by GDF, the Czech RWE Transgas, and Norway's StatoilHydro.

After encountering some problems gaining access to one data room in a gas control room in Kiev earlier in the week the monitors have now been given satisfactory access to the important flow stations and are confident that no gas is flowing through Ukraine.

WHAT IS TECHNICAL GAS?

Gas compressors or pump stations are usually needed every 40-100 miles to keep up pressure and keep the fuel moving along the pipelines stretching for hundreds of kilometers across Ukraine.

The compressors work by burning a small amount of the gas they compress to drive the turbines and move the key winter heating fuel through the pipeline.

(Compiled by Daniel Fineren)