[Steam-engine] Nichols 'D' valve

[David Myers]

Working on a Nichols & Shepard 20-70 with valve issues
(ie; wear).  Am I correct that the steam is the only
thing holding the valve to the ports?  There shouldn't
be any side pressure to the valve rod, right?  In
other words, the valve should just float in the yoke?
Also, how much end-play should you have between the
yoke and the valve?  The original valve has been
obviously modified so we are using the one off the
parts engine (same casting number so should work). 
Just want to get the installation right.  The only
other information I have on valves is setting them. 
The old one had been shimmed with a wedge of wood to
help hold the valve against the ports, not good.
Any help would be much appreciated.

=====
Dave Myers
Paw Paw, Michigan

In the heart of  Michigan's wine country.


		
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