Front matter 6 Model Selection How to Obtain the Air Consumption/How to Read Graphs (6), (7) How to Obtain the Required Air Volume/How to Read Graph (8) In equipment that used a cylinder, air consumption is the volume of air that is consumed in the cylinder, or in the piping between the cylinder and the switching valve, every time the switching valve operates. This is necessary for selecting a compressor and for calculating the running cost. The required air volume is the volume of air that is necessry for operating a specified load at a specified speed, and it is necessary for selecting the F.R.L equipment or the size of the upstream piping. Note)In selecting a compressor, the temperature drop, leakage, and consumption by the intermediary equipment must be taken into consideration. Thus, select one with a generous capacity, with a discharge that exceeds the total air consumption indicated above. (Reference: At a minimum, select one with 1.4 times the volume; select one with a higher volume as needed.) 1.Operating pressure 50 PSI  Cylinder stroke 30 inch  Bore size 1.25 inch  Air consumption . 0.5 l(ANR) 2.Operating pressure 50 PSI  Piping length 20 inch  Bore 0.179 inch  Air consumption . 0.1 l (ANR) 3.Total air consumption = (0.5 + 0.1) x 10 x 5 = 30 l/min (ANR) Example: When 10 air cylinders with a 1.25 inch bore size and a 3 inch stroke are used at a pressure of 50 PSI, what is the air consumption of their 5 cycles per minute? (A 20 inch tube with a 0.179 inch bore is used for piping between the cylinders and the switching valve.) Obtain the cylinder’s air consumption and its required air volume. Cylinder’s air consumption and its required air volume. Step 1 Step 2 Step 3 Step 3 Graph (6) Cylinder’s Air Consumption (For one cycle) Cylinder stroke (in) Air consumption (l (ANR)) Air consumption (l(ANR)) Operating pressure (PSI) By using Graph (6), obtain the air consumption of the air cylinder. Seek the point at which the operating pressure (diagonal line) intersects with the cylinder stroke, and from that point, perpendicularly extend a vertical line upward. From the point at which it intersects with the bore size (diagonal line) of the cylinder to be used, look sideways (Either to the right or left) to obtain the air consumption that is required by one cycle of the air cylinder. By using Graph (7), obtain the air consumption of the tube or steel pipe in the same way as in Step 1. Obtain the total air consumption per minute as described below. (Air consumption of air cylinder + Air consumption of tube or steel pipe) x Number of cycles per minute x Number of cylinders being used = Total air consumption [Unit: l/min (ANR)] By using Graph (8), obtain the air cylinder’s required air volume. Seek the point at which the operating pressure (diagonal line) intersects with the cylinder stroke, and from that point, perpendicularly extend a vertical line upward. From the point at which it intersects with the bore size (diagonal line) of the cylinder to be used, look sideways (Either to the right or left) to obtain the air consumption that is required by one cycle of the air cylinder. Example:What is the required air volume for operating a cylinder with a bore size of 1.25 inch, at pressure of 50 PSI, and at a speed of 10 inch/s? How to read: Operating pressure 50 PSI  Maximum piston speed 500 mm/s  Bore size 1.25 inch  Then, a required air volume 30 l/min (ANR) can be obtained. Step 4 100 10 1 0.1 0.01 0.001 100 10 1 0.1 0.01 0.001 40 30 20 10 5 3 0.5 1 25 75 125 50 100 150 Bore size (in) 2.00 1.50 1.25 1.06 0.88 0.75 0.56 0.44