Activity 3.2 – Fluid Power Calculations
1.) A pneumatic system produces 100 lb/in2 gauge pressure. A cylinder will press an adhesive label onto a product. It has been determined that 5 lb of force is optimal to complete this task. What is the required area of the pneumatic cylinder? What is the required diameter of the pneumatic cylinder?
2.) A hydraulic lift system utilizes two 3 inch diameter cylinders. Workers must determine how much the system is capable of lifting safely. The system runs at a gauge pressure of 2000 lb/in2. What is the area of each piston? How much is the system capable of lifting?
3.) The gauge pressure of a pneumatic cylinder reads 20 lb/in2. The volume is 30 in3. The cylinder is compressed until the gauge reads 60 lb/in2. Assume standard atmospheric pressure (14.7 psi). What is the absolute pressure before and after the cylinder gas is compressed? What is the volume in the cylinder after the gas is compressed?
4.) The air temperature in a 28 in3 container with a free sliding piston is initially measured at 45 °F. The temperature is raised to 200 °F. What are the absolute temperature readings initially and after the temperature has been raised? What is the new volume of the container?
5.) A flow meter is attached in a hydraulic line that measures 12 gal/min. The line has an inside diameter of 1.5 inches. 231 in3 = 1 gallon. What is the flow rate measured as in3/min at the meter? What is the cross sectional area of the line? What is the velocity of the fluid as it passes through the meter?
6.) Your 800lb NASCAR stock engine sits on a hydraulic lift platform. The lift cylinder is 0.5 ft in diameter. The engine must be lifted 2 feet before you and your buddy Cooter can slide it onto the workbench for repairs. It’s important to hurry, because you need the engine working for the big race on Saturday. Fortunately, you have a hydraulic pump. The cross sectional area of the pumping cylinder is 0.75 in2. What pressure must be exceeded by the pump (in psi) to lift the engine? What force is required at the pump? What volume of fluid will the pump have to move into the lifting cylinder to lift the engine the 2 feet required to get it on the workbench?
7.) A hydraulic press will press-fit two components together in an assembly process. The system must generate at least 775 lb of force to perform the press-fit. The piston at the input cylinder is pushed with a force of 250 lb and has an area of 30 in2. The output can use up to 15 cylinders that are each 30 in2. How much mechanical advantage is required to gain the necessary force? How many cylinders are needed?