41. Its balanced slide valves were arranged above the cylinders and were actuated by Stephenson link motion through rocker shafts. 42. They had slide valves , which was unusual on a superheated locomotive, instead of piston valves like the Class Hd. 43. There were Corliss valves on the HP cylinder and slide valves on the LP, in fact a classic Lancashire configuration. 44. A series of differently sized rubber plugs pumped down inside the casing open and then later close the sliding valves . 45. Early designs used the D slide valve but this has been largely superseded by Piston valve or Poppet valve designs. 46. The 11Bs therefore emerged as a robust and substantially enlarged evolution of GCR Class 11, with the then-conventional slide valves . 47. The flow of spent catalyst to the regenerator is regulated by a " slide valve " in the spent catalyst line. 48. Specifically, the tests are designed to determine whether one of the two slide valves that help move the rudder is jammed. 49. Preston Services have stated that there were both slide valve and piston valve versions, only 247 were made between 1934 and 1962. 50. While the slide valve variant was only available as a kit, the piston valve version was available as a complete engine or kit.
