RB Series Hose Brake Valves

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.

Code	Housing Type	Connection1	Connection2	Size	Closing Flow Rate (GPM)	Closing Flow Rate (L/min)	HYDAC P/N	HYDAC Model Code
Cartridge Only
E		-	-	SAE 9/16-18	1-4	4-15	710031	RBE-SAE 9/16-18-X-15LPM STD. SET
				SAE 3/4-16	1.6-12	6-45	710032	RBE-SAE 3/4-16-X-45LPM STD. SET
				SAE 1 1/16-12	6.5-32	25-120	710033	RBE-SAE 1-1/16-12-X-120LPM STD. SET
Cartridge Valve in Housings
XB		SAE Straight Thread Port	SAE Straight Thread Stud End	SAE 9/16-18	1-4	4-15	2069016	RBXB-SAE 9/16-18-X-15LPM STD. SET
				SAE 3/4-16	1.6-12	6-45	2062157	RBXB-SAE 3/4-16-X-45LPM STD. SET
				SAE 1 1/16-12	6.5-32	25-120	2061898	RBXB-SAE 1-1/16-12-X-120LPM STD. SET
XB		NPT Port	NPT Male Connector	NPT 3/8	1-4	4-15	2062818	RBXB-NPT 3/8-X-15LPM STD. SET
XX		SAE Straight Thread Port	SAE Straight Thread Port	SAE 1 1/16-12	6.5-32	25-120	2063213	RBXX-SAE 1-1/16-12-X-120LPM STD. SET
CC		NPT Male Connector	NPT Male Connector	NPT 3/4	1.6-12	6-45	2062871	RBE-NPT 3/4-X-45LPM STD. SET

Closing Flow Rate (min - max) (from 2 to 1)

• To avoid the activation of hose break valves on flow surges, the closing flow rate should be at least 20% above the normal flow rate.
• Valves are shipped with maximum closing flow setting. Closing flow can be adjusted according to the curve on the next page. If closing flow must be set by factory, please specify when ordering.

Recommendations

Hose break valves, type RBE must only be used to safeguard users in the event of hose breaks. They must not be used as switching valves for repeated closing actions.

If closing actions occur during normal operation, the setting of the hose break valve is not suitable for the operating parameters of the system. The hose break valve must be replaced by a new one with a modified setting.

In order to prevent hose break valves reacting to flow rate fluctuations inherent in the system, e.g. due to switching of directional valves, the actuating flow rate should be at least 20% above the normal maximum system flow rate. If high viscosity fluctuations occur, the valves must be set to a higher actuating flow rate to ensure trouble-free operation at high viscosity. However, the valves must still react at a low viscosity. Since this range depends largely on the system, whose operational flow rate fluctuations can also depend on viscosity, the appropriate setting for the valve is best determined on site.

Sizing Hose Break Valves

In order for a hose break valve to work properly there must be a difference between the normal operating flow rate (from pump) and the emergency flow rate created by a hose or line break. The emergency flow rate must be significantly higher than the normal operating flow. Why? The hose break valve is designed to only be closed in an emergency situation. These valves should not be cycled (opened and closed) with the system. Cycling the valve and/or excessive vibrations will lead to premature failure of the valve components.

How do you determine the emergency flow rate? You must perform a test with the actual system in a hose break simulation. This test should be run with the minimum load on the cylinder/lift to determine the minimum emergency flow rate for the system. To test, break the line open or open a directional valve and allow gravity to pull down the cylinder/lift. The flow rate measured during this test is the emergency flow rate.

The hose break closing flow rate setting is adjustable and should be set to close at a flow rate between the normal flow rate and the emergency flow rate. The closing flow rate should be set at least 20% higher than the normal flow rate, and should be set at least 20% below the emergency flow rate.

How do you set the closing flow rate for the valve? The gap between the poppet and the valve body is adjustable by means of the lock nut and adjustment nut on the end of the poppet. The larger the gap, the higher the closing flow rate for the valve.