On a Stuart 10V vertical steam engine, what holds the sliding valve
against the cylinder block during operation? Closely machined
tolerances between sliding valve, cylinder block, and valve rod? Or
maybe shims between sliding valve and valve rod?

Or does the steam pressure in the valve chest force the sliding valve
against the cylinder block?

Sorry, I am a total novice at this, so far! So please be very
specific, and very gentle.......!

Lee Carkenord

wrote:

On a Stuart 10V vertical steam engine, what holds the sliding valve
against the cylinder block during operation? Closely machined
tolerances between sliding valve, cylinder block, and valve rod? Or
maybe shims between sliding valve and valve rod?

Or does the steam pressure in the valve chest force the sliding valve
against the cylinder block?

Sorry, I am a total novice at this, so far! So please be very
specific, and very gentle.......!

Lee Carkenord

Not sure, but I lean towards the close machining and the steam
pressure, rather than shims.

I do know that Tee Publishing have a book on the building of this
specific steam engine, aimed directly at novice builders.

I found this info at http://www.fotec.co.uk/mehs/tee/


BUILDING A VERTICAL STEAM ENGINE FROM CASTINGS by Andrew Smith &
Pengwern
This book is based on the most popular of Stuart Turner models, the No.
10 range. It covers the machining of all parts of the 10 V and 10 H
engines and indeed these machining principles can be applied to any
vertical steam engine of similar construction. £6.95 (B)

They have lots of good books.:-)

Cheers
Trevor Jones

--If you build it right the sliding valve should be free to
"float" on the valve rod; confined top/bottom with pairs of jam nuts on
the rod, with very little play. Lap the sliding valves and their mating
valve chest faces to minimize leakage. Steam pressure should hold them
together..

--
"Steamboat Ed" Haas : Whatever happened
Hacking the Trailing Edge! : to Eiffel Plasterer?
http://www.nmpproducts.com/intro.htm
---Decks a-wash in a sea of words---

On 1 Jan 2006 19:45:42 -0800, wrote:

On a Stuart 10V vertical steam engine, what holds the sliding valve
against the cylinder block during operation?

Same thing as any slide valve - steam pressure. This is why they were
always regarded as the simpler (and older) design than piston valves,
even back when machining a flat surface was an expensive manual task.