Cylinder FAQ

Is it possible to make the stroke of a cylinder adjustable?
Yes. Double-acting cylinders may be ordered with a common rod that protrudes from both cylinder end caps. A nut may be placed on one rod end to retain spacers that will limit the stroke distance. Be sure to guard the spacer end because “pinch points” will be present.
How do I calculate the air consumption of a cylinder?
Example: Determine the air consumption of a 2² bore cylinder with a 4² stroke operating 30 complete cycles (out and back) per minute at 80 PSI inlet pressure.

1.) Find the area of the piston by converting the bore diameter into square inches.
(2 in. bore/2)² x 3.1416 (pi) = 3.14 sq. in.
2.)Determine consumption per single stroke.
3.14 sq. in. x 4 in. stroke = 12.56 cu.in.
3.)Determine consumption per complete cycle (Disregard displacement of piston rod because it is generally not significant).
12.56 cu.in. x 2 = 25.12 cu.in. per cycle.
4.)Determine volume of 80 PSI air that is consumed per minute.
25.12 cu.in. x 30 cycles/minute = 753.6 cu.in./min. of 80 PSI air
5.)Convert cu.in. to cu.ft.
753.6 cu.in./min./1728cu.in/cu.ft = .436 cu.ft./min. 1728 cu.in/cu.ft.
6.)Convert air compressed to 80 PSI to “free” (uncompressed) air.
(80 PSI + 14.7 PSI)/14.7 PSI = 6.44 (times air is compressed when at 80 PSI) 14.7 PSI.
7.)Determine cubic feet of free air used per minute.
0.436 cu. ft. x 6.44 compression ratio = 2.81 cu. ft. of free air used per minute.
8.)So, the consumption rate of a 2" bore, 4" stroke cylinder operating 30 complete cycles per minute at 80 PSI is 2.81 SCFM (Standard Cubic Feet Per Minute) of free air. “Standard” means at a temperature of 70•F and at sea level.
How do I prevent a cylinder from impacting at the end of its stroke?
Generally, it is best to order your cylinders with built-in cushions if you anticipate unacceptable end-of-stroke impact. Cushions decelerate the piston rod through the last 11/16" of stroke. The degree of cushioning may be adjusted by means of a needle control in the cylinder head. See the Dyna-mation and HD Series cylinder sections.
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