Contains the piston, the cylinder, and the valve piston, all in a steel casting called the cylinder saddle which also supports the boiler and smokebox. Steam enters the steam chest from at the top from the throttle through holes at each end of the valve piston, which determines the timing of the piston stroke, and also sets the efficiency of fuel use. The K-28s have high-pressure cylinders because the steam works at its highest expansion and heat, so the steam chest must withstand internal pressures up to 200 psi (pounds-per-square-inch) and steam temperatures as high as 500°.
Quick facts
How strong is an engine?