Steam thermo-barrels to allows 15c, 165c and 500c steam to be barrelled like other fluids.
Only 165c and 500c are actually useful for power generation and steam distribution.
If anyone has any further ideas around this let me know. It's a throwback to the times when the fluid-wagon was not a thing so maybe nothing more to do. We're using it for bot resupplies with a pure bot world we're doing. (No trains or massive belt bus either)