Here's a setup which always worked for me:
Boiler (Steam Generator) must be set to 220 bar pressure and 1 mb/tick output. You should put 10 buckets of distilled water in it as well.
Both fluid distributors must be set to -Concentrate- and the outlet must be set to the bottom side (shift-click with a wrench on the top side). The idea is to have all the distilled water back on the boiler.
Condenser must have 1 Heat Vent to keep up with the rest of the system speed, also it will need a Fluid Ejector upgrade settled to eject only towards the side where the nearest fluid distributor is located (to the west side in my example). It will need power to operate, so, don't forget to put a cable to draw this power from the engine right below.
Topmost steam turbine must have a Fluid Ejector upgrade settled to eject only towards the fluid distributor beside it, the turbine at the bottom must have another upgrade as well but it should eject (distilled water) right back into the boiler.
You should apply 200 hu/t to the boiler in order to produce superheated steam, one heat exchanger will produce only 100 hu/t, so, you will need 2 fully operative heat exchangers next to the boiler for this to work, in my example they should be placed north and south of the boiler. Super heated steam will be produced once the boiler reaches 374 degrees.
To set a ejector upgrade, shift click while holding the upgrade in the hand, you could use any block on the world, just make sure to click over the side you need the upgrade to eject to.
The condenser is the key to avoid steam explosions.