A rotary joint must provide a sealed connection between a fixed pressurized supply line and a rotating machine or cylinder.
Rotary joints are used to convey the following fluids: hydraulic oil, air, or vacuum. Thanks to the rotary joint, a fluid can be transmitted to an actuator at a certain pressure from rotating components of the machine (e.g. the machine shaft) to transmit power.
Rotary joints are designed for use in potentially non-explosive environments and for non-flammable fluids.