Sounds like a fun project.  Making a reasonable valve shouldn't be tricky - but...  steam is a lot like wind, there is a lot to it, a lot of research has been done and to be even reasonably efficient I think a lot of research is involved.  Last time I ran mine I carefully weighed the coal and monitored KWH output and came up finding that I was running between 2-4% (depending on the quality of the coal which I am not sure) efficient.  (probably I was running about 3%)  Of course, when I fired it all up all the equipment was at -4 deg F!  I expect better efficiency in the summer.

'Any links would help. I've looked until I'm fed up but I'm still looking.
Yep switching from wind to steam.'

Steam is great fun and workable, but to get a steam system thats not very labor intensive will involve a lot of work/money.  Wind is free - once you get it setup there's very little cost/labor involved to keep it running.  If I was to say such a rediculous thing (sorry) that 'Im switching from wind to steam' and actually kept my house/shop powered up I would have a full time job cutting wood and playing 'engineer'.  You don't walk away from a steam system, it requires constant attention.  Lots better than peddling for power but compared to a diesel engine running on vegi oil (if you're worried about renewable energy) or an internal combustion engine running off a gasifiers - steam is a hell of a lot of work, takes a lot of fuel and a lot of water.