21. Eighteen of these locomotives were rebuilt with piston valves and superheated boilers in the 1930s. 22. Conventionally, piston valve locomotives had inside admission, whereas outside admission was used with slide valve locomotives. 23. *The inlet valve ( not the piston valve ) is a " sprung bash valve ". 24. The class were fitted with a steam chest and slide valves located beneath the piston valves . 25. They had outside Gooch valve gear and piston valves, a very early use of piston valves . 26. They had outside Gooch valve gear and piston valves , a very early use of piston valves. 27. These proved successful but insufficiently so to be chosen for production locomotives over the reliable piston valve . 28. Fourteen were equipped with superheated boilers, bore cylinders and inside admission piston valves , and were reclassified to. 29. It used piston valves and eccentric motion. 30. While the Class 10 had outside admission valves, the Class 10-2 superheated used inside admission piston valves .
