slide valve

Noun

slide valve (plural slide valves)

1. A valve in a steam engine, designed to slide back and forth to cover and uncover the openings through which steam enters the cylinder.
   • With its long tapered cowcatcher, massive headlamp and enormous diamond smokestack behind, wagon-top boiler, high running-plate above the driving-wheels reached from a front door in the square side-window cab, cylinders with slide valves mounted on top, and double bogie tender, General in its...1942 February, “Notes and News: An Historic American Locomotive”, in Railway Magazine, page 56
   • The inside cylinder, with its piston-valve, had its crank set at 135deg. to the outside-cylinder cranks, which were at the usual 90 deg. to one another; the latter cylinders had slide-valves.1961 November, Voyageur, “The last of the Midland compounds”, in Trains Illustrated, page 675