STEAM ENGINE : SLIDE VALVE ANIMATION

This example shows the relationship between the position of the slide valve and the piston for three cases, namely:

Note that in the latter two cases the slide valve has the same dimensions.

Particular attention should be given to the ingress of live steam and the egress of exhaust steam in relation to the cylinder, as well as to the positions of expansion, compression and lead steam.

The user may control the animation by means of the buttons at the bottom of the form. Two modes of operation are possible, namely "Continuous : Loop" or "Manual operation".

To understand what is going on it will be found instructive to use the "Manual" and "All three models" options and step through the positions one at a time, having positioned the three model images so that they are all visible on the screen at the same time. The following table shows the principal features in the left and right parts of the given cylinder:

  No lap or lead Lap but no lead With both lap and lead
Position Left Right Left Right Left Right
1 Exhaust Steam Exhaust Steam Exhaust Steam
2 Exhaust Steam Exhaust Steam Exhaust Steam
3 Exhaust Steam Exhaust Steam Exhaust Steam
4 Exhaust Steam Exhaust Steam Exhaust Steam
5 Exhaust Steam Exhaust Expansion Exhaust Expansion
6 Exhaust Steam Compression Exhaust Compression Exhaust
7 Neither Neither Compression Exhaust Lead steam Exhaust
8 Steam Exhaust Steam Exhaust Steam Exhaust
9 Steam Exhaust Steam Exhaust Steam Exhaust
10 Steam Exhaust Steam Exhaust Steam Exhaust
11 Steam Exhaust Steam Exhaust Steam Exhaust
12 Steam Exhaust Steam Exhaust Steam Exhaust
13 Steam Exhaust Steam Exhaust Steam Exhaust
14 Steam Exhaust Steam Exhaust Steam Exhaust
15 Steam Exhaust Steam ExhaustSteamExhaust
16 Steam Exhaust Steam Exhaust Steam Exhaust
17 Steam Exhaust Expansion Exhaust Expansion Exhaust
18 Steam Exhaust Exhaust Compression Exhaust Compression
19 Neither Neither Exhaust CompressionExhaustLead steam
20 Exhaust Steam Exhaust Steam Exhaust Steam
21 Exhaust Steam Exhaust Steam Exhaust Steam
22 Exhaust Steam Exhaust Steam Exhaust Steam
23 Exhaust Steam Exhaust Steam Exhaust Steam
24 Exhaust Steam Exhaust Steam Exhaust Steam

Note:

User Controls:
  
Select Model:
  
Play Mode:
Image Number:
Speed:
  
Actions:Key:
Steam
Expansion
Exhaust
Compression
Lead
 
 
  
Upper Image : #
Middle Image : #
Lower Image : #
(1) No Lap or Lead
(2) Lap but no Lead
(3) Lap and Lead