Instrumentation & controls has introduced hydraulic/pneumatic presses. These presses are specially designed for economy when production rate is to be fast. These presses need either compressed air supply at 100 psi or electric supply to operate. Compressed air is used to increase oil-pressure that is then fed to the main hydraulic cylinder to get a high ram force. Thus relatively long approach stroke of the cylinder is accomplished at low [generally 60 to 100 psi] pressure. It includes advantages like high efficiency and precision; smoothness and control of hydraulic operation without complicated pump; and high-pressure hydraulic valve installations. And the shift from low approach stroke pressure to high work pressure is automatic with time devices and appropriate circuitry. It offers capacities of 2, 4, 8, 15, 30 and 50, tonne; stroke are of 50 mm, 75 mm, 100 mm and 150 mm; and power stroke is of 6 or 8 or 12 mm. Compressed air force is intensified to high force by air hydraulic booster. Thus advantage of hydraulic force is achieved by using compressed air available. It is highly suitable for operations like blanking, punching, pressing, bending, forging, etc. This is ideal for marking, coining, stacking, etc.
