Cylinder design is dependent mainly on the working pressure and diameter range. Cylinder bodies can be castings of gray iron, nodular (ductile) iron, or steel. Forged and fabricated steel cylinders are also available for higher pressures. Figure 300-26 shows a variety of cylinders. All of these cylinders have liners. Many of the cylinders offered for high-speed compressors (Class B and D) do not have liners.
Note that cylinders are available in the tandem arrangement having two sizes of pistons. This rather uncommon arrangement allows two cylinders to be placed on one crankthrow. Usually both pistons are single-acting, but in some designs only one of the two will be double-acting.