Hydac_Velocity Fuse

HYDAC Hose Break Valves eliminate uncontrolled movements of the actuator in case of line rupture. They are commonly applied with dead weight cylinders.

These valves are volume limiting flat seat valves.

At normal flow, the poppet is held open by a spring with enough force to counteract the force on the poppet created by the flow.

When the supply line is ruptured, the flow from 2 to 1 exceeds the specified flow rate, the P across the poppet creates a force greater than the spring force and closes the valve. This closing flow rate is adjustable. The valve opens automatically by pressurizing connection 1.

Depending on the pressure P, the leakage rate through the valve is approximately 0 to 6 in³/min. If this is excessive, the valve threads can be sealed and made leak-free.

The valves are installed between actuators and possible line breakage points.

A cartridge-type valve can be installed into an actuator port.

A housing-type valve can be installed close to the actuator or even directly into the actuator itself.


Hydac_Valve_Velocity Fuse_RBE Hydac_Valve_Velocity Fuse_RB
Type RBE Cartridge Unit Type RB Housing Unit


Engineering Data

Design Flat Seat Valve
Mounting Method RBE Cartridge
RB.. Housing Valve for In-line Installation
Mounting Position Optional
Direction of Flow 1 to 2 Free Flow
2 to 1 Free Flow; valve automatically closes if flow exceeds preset level
Fluid General purpose hydraulic oil. Consult HYDAC for other media
Operating Pressure Ratings P Max: 5000 psi (350 bar)
P Min: 145 psi (10 bar)
Fluid Temperature Range -4° to 176°F (-20° to 80°C)