Design Advantages and Features

High Stability

The novel rotor and stator design used in the Hydra-Brake® provides a unit of high stability when used with a constant pressure water supply source and properly selected control valves.

Wide Range Ability

Hydra-Brakes® cover a wide horsepower/speed range. At a chosen speed and with proper controls, power absorbed can be controlled from 100% to 2% of rated power by changing the water level in the unit. In addition, the stationary discs are easily removed to permit even lower absorption. An atmospheric drain below the level of the brake and a water compartment vent are necessary to obtain this wide range.


Flange-mounted Hydra-Brakes® are lightweight and compact. These features permit the brake to be mounted easily and quickly and readily moved from one location to another. A splined floating shaft, connecting prime mover to brake, allows direct flange mounting of the brake without the normal alignment problems.

Low-Cost Installation

Hydra-Brakes® are not only low in initial cost compared to other types of absorption dynamometers, but they are also inexpensive to maintain. Surfaces subjected to corrosion are amply protected, and corrosion-resistant materials are selected. Due to the simplicity of design, the brakes can be easily disassembled for periodic inspection.

Other Advantages

Most models are provided with positive-type water shaft seals consisting of a spring-loaded carbon ring operating against an optically flat, stainless steel rubbing ring. These seals are operating satisfactorily at speeds of 23,000 rpm. Hydra-Brakes® are usually provided with ball bearings that can be lubricated with either oil or grease, depending upon operating speeds. Means may be provided for mounting bearing thermocouples, and a tachometer drive can be furnished if desired. Also available are special flexible inlet and discharge water fittings which eliminate long hose connections.