page_title: Single- and double-acting cylinders
section_title: Double-acting
hierarchical_section_title: Single- and double-acting cylinders / Double-acting
caption_attribution_description: Buffalo horizontal steam engine (New Catechism of the Steam Engine, 1904).jpg
context_page_description: Reciprocating engine cylinders are often classified by whether they are single- or double-acting, depending on how the working fluid acts on the piston.
context_section_description: A double-acting cylinder is a cylinder in which the working fluid acts alternately on both sides of the piston. In order to connect the piston in a double-acting cylinder to an external mechanism, such as a crank shaft, a hole must be provided in one end of the cylinder for the piston rod, and this is fitted with a gland or "stuffing box" to prevent escape of the working fluid. Double-acting cylinders are common in steam engines but unusual in other engine types. Many hydraulic and pneumatic cylinders use them where it is needed to produce a force in both directions. A double-acting hydraulic cylinder has a port at each end, supplied with hydraulic fluid for both the retraction and extension of the piston. A double-acting cylinder is used where an external force is not available to retract the piston or it can be used where high force is required in both directions of travel.
caption: Typical horizontal steam engine with double-acting cylinder
exif: {}