I use version 1.19.2-2.0.71.

I can't manage water/steam to stay between a reactor and a turbine. It always vanishes. The turbine is not set on vent, it is set on keep all coolant!

I build a reactor right next to a turbine. Each has an active output port and a passive input port. I use Mekanism mechanical pipes connecting an active output port with a passive input port.

I fill the reactor from another side from a creative water tank until full. Then i cut the connection. I activate the turbine and the reactor. Steam gets produced. The turbine spins up. But there is no water in the pipe connecting the turbine output. Where is the water? The reactor empties its water tank and stops producing steam after that.

I managed to get different weird behaviors. The second one is with only passive ports. I configure the pipes to pull and push into the passive ports. In this configuration, water manages to reach the reactor.

First i fill the reactor with water again. Then i power reactor and turbine on. The water in the reactor gets used up in full ( in my test setup, 880 mb/t) even tough, the steam has nowhere to go, as the pipe is full and the turbine as well. The turbine spins up and is set to 750 mb/t. As soon as the water tank in the reactor hits zero, the steam production decreases to exactly 750 mb/t, which is expected, as that is the water, that is coming from the turbine. But the steam tank in the reactor decreases now. Even though turbine and reactor both use exactly 750 mb/t. As soon as the steam tank hits zero, both stop working. All coolant is gone!

Next test. If i set up two tanks with 256 buckets volume, one empty to take the water output of the turbine, and one filled with water as coolant for the reactor. And then connect the steam output of the reactor with the steam input of the turbine, in theory, there should be 256 buckets of water in the output tank after the input tank is emptied. If no water is lost magically. Here my setup:

The result is, that only 86 buckets of water arrive at the output water tank!

Ok i continue my testing. This time i empty a 256 bucket water tank into a reactor, which is just super hot. Around 3000°C. And collect the steam created. I always end up with 217.6 buckets of steam! (If i reduce the temp of the reactor, so that it stays cool around 400°C, its intake fluctuates a bit, and i end up with a slight diverged amount of steam. Like 217.433 to 217.867 buckets.)

Now the same test with a turbine. Here is the basic setup, followed by a behavior description based on the order and state of the turbine:

Turbine is always set to "Do not vent coolant"! I use advanced mechanical pipes from mekanism, which transport 1000 mb/t.

If the turbine is already ON without any steam in it and set to 1000 mb/t (whether already spinning or from total stop, whether engaged coil or not). And then just connect the steam input, the turbine accelerates and uses the steam, but it does NOT output water!

If the turbine is OFF without any steam in it and set to 1000 mb/t (whether already spinning or from total stop, whether engaged coil or not). I connect the steam input, so that it fills the turbine. And start the turbine now, there is water output. I end up with 255 buckets of water. 1 bucket gets deleted.

And here an interesting find:
If the turbine is already ON without any steam in it and set to 999 mb/t (whether already spinning or from total stop, whether engaged coil or not). And then just connect the steam input, the turbine accelerates and uses the steam, it does output water! Again a fraction gets deleted, this time 256 mb. Which correlates with the amount, which is the last tick the turbine tries to suck steam from its tank, but has only less than its desired amount left, 256 mb!

I assume, that similar to the assumptions here 76, the turbine just does not output liquid, if it consumes steam, and leaves the steam tank empty afterwards. This is the case, if the input steam matches the consumption, as each tick the steam tank gets emptied, if the input is less than the turbines consumption, or if there is no further input of steam and the last tick of steam consumptions happen.

Expected is, that the turbine outputs exactly the steam it consumes as liquid!