Boosters or intensifiers are used to create a high pressure output from a low pressure input. Much like how an electrical transformer works by trading current for voltage, a hydraulic booster transforms a larger volume of low pressure fluid into a smaller volume at a higher pressure.
Gimme a boost?
A booster unit is comprised of two sections, a drive cylinder (input) and a high pressure chamber (output). As a fluid is supplied to the drive cylinder this causes the piston and ram to extend. As the ram extends into the chamber the internal volume is compressed creating a pressure. The difference in area between the piston and ram determines the boost ratio which is the relationship between the pressure and volume. For example, a booster with an 8:1 ratio will have an output of 1/8 of its input volume at 8 times the input pressure.
Boosters can be designed to operate on a variety of fluids and can use different fluids on both the input and output sections. A common design is a pneumatic booster where shop air pressure is used to create high pressure hydraulic oil for use in a cylinder. For example a 5” bore pneumatic booster with a 1” dia ram has a ratio of 25:1, when supplied shop air at 80 psi. the unit will generate a hydraulic oil pressure of 2000 psi. This can be very useful where space is limited as the booster unit can be located remotely from the cylinder and can generate a high pressure with only a common air supply. Using the 25:1 ratio pneumatic booster above in a further example if the 2000 psi output is used to drive a 2” bore hydraulic cylinder the cylinder will extend with approximately 6200 lbs of force. To achieve the same 6200 lbs of force directly with a pneumatic cylinder at 80 psi would take a 10” bore cylinder.
With available output pressures exceeding 40,000 psi and a large range of possible fluids, boosters can be a great solution to some tricky problems.
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Image credit: Vichaya Kiatying-Angsule