• Outside/steam lap (OL) = 0
• Inside/exhaust lap (IL) = 0
• Lead angle (LA) = 0
• Exhaust relief (ER) = 0
• Link-up (LU) = 0

The slide valve faces are the same width as the steam ports therefore the valve is fully closed only momentarily. The valve eccentric (magenta pointer) is 90^o ahead of the piston crank (green pointer) so the closure occurs at top and bottom dead centre.  This gives no steam expansion phase and no cushioning (shown as grey in the cylinder). The eccentric throw allows the ports to fully open only momentarily at mid piston stroke.

The red and blue ray plots indicate the amount the upper steam port is open to steam and exhaust respectively.  The radius of the green cardioid plot indicates the volume of the cylinder above the piston (relative to the eccentric pointer).

• See Valve with Lap & Lead
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