Mutual Improvement Class

1
Mutual Improvement Class

• Valves and Valve Gears

2

• Slide and Piston Valves

3
The locomotive valve of any kind must, in
conjunction with the valve gear, so control the
valve that the following events take place in
succession in the cylinder   (a) A period of
admission of live steam up to a point of
cut-off.   (b) A period of expansion up to a
point of release.   (c) A period of release for
the used steam.   (d) A period of compression
after the valve has closed.   (e) A brief period
of pre-admission of live steam before the piston
commences its working stroke.   In the events
just indicated the valve has three distinct
duties to perform   (a) closes both steam ports
when in its central position   (b) admits steam
to one end of the cylinder only at one
time    (c) opens to exhaust at one end of the
cylinder at least as soon as it opens to admit
steam at the other.
4
(No Transcript)
5
(No Transcript)
6
(No Transcript)
7
(No Transcript)
8
(No Transcript)
9
Mutual Improvement Class
Valves and Valve Gears Part 2
10
(No Transcript)
11
(No Transcript)
12
(No Transcript)
13
Compare the standard Walschaert valve gear with
that fitted on USA Tank. Whats different and why?
14
Note that the return crank is 90 degrees in front
of the big end
15
Loco in mid gear
16
Loco in fore gear, note that the die block is
raised rather than lowered as is usual with
Walshaert valve gear
17
Loco in back gear
18
Showing lubrication to valve and piston glands
19
Pressure relief and oil pot fitted to front
cylinder cover
20
Automatic drain cocks
21
Snifting Valve
22
Thats it for the classroom, shall we go and have
a look at the real thing?