Thx all for your answers. First I reduced the needs and once all was well balanced I added some production building and all is good now.
I have to learn on fluids rules I think.

Thx for your answers. So I have to build more refineries or more petrol pipe or both?

betrok wrote:You have different settings on power switch for heavy oil cracking, i guess it can be your problem.

I've changed it for tests, I put it back again and no changes.

batorfly wrote:Maybe i'll check it, but i don't know if i will have time today.

No problem, it's nice to try help
The thing I really don't understand is that I have the exact same configguration of refineries in another game and it works fine!

I finally tried to build dedicated water and petrol network from main tanks for petrol and from a deidcated water pump: It doesn't change anything so the problem is not due to the sources.
I upload the save game.

Thx for this optimization tip, I change the inserters to fullfill your advices. It still not explain why the left group of refineries do not have a normal behaviour. I tried to cut all and put an alone refinery, filled with the same water and petrol and with only 3 tanks as ouputs...the results are ...

I put another tank of heavy oil and it didn't change anything...

Tanks of heavy oil are almost full but not completely, the logical circuit are smart enough for that. Actually I have 19k heavy oil on the left group (the one which doesn't work) and light and gas are empty. 24k heavy oil on the right group, 24k light and 24 gas, all works fine for this group.

The left group doesn't work, but it's the exact copy of the right one! The northest tank is for heavy oil (almost fuel in the both group), under it is the light oil (almost empty on the left and full on the right) and on the bottom is the gas (empty on the left, full on the right). I verified and pe...

North part:


South part:


Detail:
The left group of refineries doesn't work properly:

The amounts :
1 to 5 gas
2 to 5 light oil
70 heavy oil

Hi all, I have two twin refineries with the exact same configuration. They both receive the same amont of water, iol, etc...they are exactly the sames. The first one works fine but the second one not: it produces a very few amount of gas, light oil and a greater amount of heavy oil. This second refi...

Ho thanks a lot! I do not remember having pressed this key, but I have big fingers
Thx again for your answer!

I randomly have this graphic bug:

I have to restart the game to keep on playing. Anyone has an idea?

(I use windows 10 and a geforce 1080TI graphic card)