Rolling Diaphragm Cylinders, Friction-free conversion of pneumatic pressure to linear force.The advent of the long stroke rolling diaphragm as a means of low-friction dynamic sealing has led to the development of ControlAir's line of Diaphragm Air Cylinders. These cylinders provide virtually frictionless conversion of pneumatic pressure to linear force. The fact that there is no stiction or blow-by of any kind ensures accuracy, repeatability and sensitivity unheard of from conventional sliding seal air cylinders.