LOL !!! You've been hiding your light under a bushel, Electro ! And of course you are absolutely right. Yup! I know the theory. I used to work in the boiler room of the QE2....(and my Dad was a Stoker on a steam bomber in WW2 - a Lancaster if memory serves.) ;-)

This valve arrangment seems to take steam from the 'Steam Fountain' above the boiler - the bit I modelled before this, so there's a clue.
Thanks for your comments!

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All the Woes of a World by Jonathan Icknield aka The Bryster

And in my final hours - I would cling rather to the tattooed hand of kindness - than the unblemished hand of hate...