Finally!!!! With QoLIII, the old turbine is gone. This thread is now mostly useless. If the new turbine has as many bugs/issues, I'll start a new thread.
In honor of @SamLogan's "Everything you need to know" series, I now present,
The Steam Turbine: Everything you need to know.
To make a turbine work you need three things.
Steam in at least one of the 5 tiles directly beneath the turbine.
One of these 5 tiles directly beneath the turbine must have a temperature of 500K or above (can be a solid tile, a liquid, or any gas - see spoiler).
The largest steam pressure under the turbine must be 3K larger than the smallest pressure (liquid/gas) in the 5 tiles located at the top of the turbine.
What happens when the requirements are met?
The steam turbine take a few moments to spin up (red bar becomes green).
Once the bar reaches green, the turbine sucks up steam underneath the turbine (up to roughly 2kg/s per unblocked port for a total maximum of 10kg/s).
The steam spits out the top (in the top 5 tiles) at exactly 425K (no matter how hot it was to start with).
You gain 2000W.
What kind of error messages will I see:
"No Wire Connected" - Connect a wire to the turbine.
"Input Blocked" - One unblocked port is enough. This message can currently be ignored.
"Underpressure" - The largest pressure steam tile under your turbine does not have 3K more pressure than the lowest pressure tile above. Either increase the pressure below, or decrease the pressure above, or both.
"Cold Steam" - The hottest tile under your turbine dropped below 500K. You'll need to heat things up.
Other Topics - Exploits/Bugs/Uses/Links/More
Each question below has several ideas in the spoiler. Some contain links, some do not. Answers might be a single word, which means you'll find examples in the unsorted links group at the bottom of this post. If you find a useful post I have not included, please let me know and I'll get it added.
Should I block ports, or leave them open?
How do I maintain the pressure difference?
How do I maintain the temperature underneath to be above 500K?
I'll add more links to the stuff above as I have time. Feel free to add links in the comments if something has helped you with this crazy contraption. For now, here are several things you can study further.
Unsorted Links to Other Forum Posts - With Commentary
Hi @Saturnus, I just checked it. The build you showed deletes steam. I started with 460 kg of steam, and the total just keeps on dropping (it's at 418 here, but 30 seconds later in my game it's down to 390kg). I was hoping the code had changed some from my last tests, but it hasn't.
To the best of my knowledge, if anything is locked in place and blocking any one of the top 5 tiles, that's what causes steam to be deleted. That's why hydrogen/oxygen, without 1 tile above the turbine, causes steam deletion. You can layer 10kg of crude, followed by 10kg of naptha on the first two layers above the turbine, and the steam deletion occurs at the same rate.
However, if you delete the petro and visco-gel (allowing steam to occupy the third level up), and then use a door pump to push the steam down, there is zero steam deletion - just checked.
Most of us currently use oxygen or hydrogen for the gas conflict in our turbines, but a layer of carbon dioxide on top of crude oil does the exact same thing, with the gas fighting from underneath. This option is more dangerous, as one tiny bit of CO2 leaking out over the ledge and to the bottom would block a port (fixable, but still dangerous), and it takes one more tile of width to let the steam back down. I don't see any reason to swap to CO2 conflicts, but they do work (haven't seen one before in the forums).
The second you do anything that causes gas or liquid to get trapped on that top layer of the turbine, you start loosing steam. For example, if you block just 1 of the 5 tiles above the turbine (using an oxygen/hydrogen trick), then when one bit of gas ends up underneath this tile, it gets stuck and can't be forced away - steam gets deleted. Hence you need all 5 tiles above the turbine open. Here's another version that traps CO2 on that top layer, and steam disappears.
Similar mechanics seem to be at play with natural vents and geyers (maybe volcanos too). There are specific spots where stuff gets emitted, but if you block those specific ports with something that cannot be moved (because of 1 element per tile rules), then odd things happen. You can force something to overproduce, or underproduce.