Hydraulic and Pneumatic Power Systems Using a hand pump, pressure of 100 PSI has been built up in a hydraulic system. The hand pump piston is 1 inch in diameter. A 1/2-inch line connects the hand pump to an actuating cylinder 2 inches in diameter. What is the pressure in the line between the hand pump and the actuator? a. 100 PSI. b. 150 PSI. c. 200 PSI.