View single post by Herb Kephart
 Posted: Mon Oct 3rd, 2016 03:27 am
PMQuoteReplyFull Topic
Herb Kephart



Joined: Thu Jul 19th, 2007
Location: Glen Mills, Pennsylvania USA
Posts: 5929
Status: 
Offline
In short, it is a way to reduce the amount of piston stroke that the valve gear admits steam into the cylinder, allowing enough steam to go in and expand, without wasting un-expanded steam by having it blow out the stack.

Quite a bit more involved than that--but in one sentience, that's the best that I could do. One thing that lots of folks have trouble grasping is that a steam engine gets its power from the HEAT in the steam, not the PRESSURE. A good engineer runs as much as possible with the throttle wide open and the cutoff as close to center as possible.

Herb



____________________
Fix it again, Mr Gates--it still works!"
Close Window