Glossary
Hydraulic Elevator
An elevator whose lifting energy is applied by pressurized liquid acting on a cylinder and plunger or piston.
A pump sends hydraulic fluid to the cylinder for upward travel. Controlled return flow allows the car to descend. Direct-plunger designs act on the car or frame without intermediate linkage; roped hydraulic designs connect piston movement to the car through wire ropes.
For building planning, the term alone does not specify travel, speed or cost; those depend on the selected product and project. Compare it with a traction elevator in Traction vs. Hydraulic Elevators, then see How Elevators Work for the trip sequence.
Sources
California Elevator Safety Orders hydraulic-elevator definitions; California hydraulic-elevator operating and control rules.