The excess flow device protects against gas leakage, for example in the case of gas barbecues, outdoor heaters or radiant heaters. As soon as a massive leak occurs in the hose assembly, the safety device shuts off the gas supply and prevents worse things.
A hose rupture or a major leak can quickly become dangerous: within seconds, unburnt liquefied gas may escape uncontrollably. A hose break‑safety device (HBS) reliably protects in such cases by automatically interrupting the gas supply.
Whether camping, barbecuing or heating – liquefied gas systems are practical, but they also carry risks, just like many other energy media. One of the most important safety components for liquefied gas systems is the hose break‑safety device. It detects when gas flow suddenly and unusually increases and immediately shuts off the supply. But how does this technology work in detail? When does it activate, and what standard values apply? In this article, we explain the functionality of an HBS, provide practical examples, and show why it is indispensable in many applications.
A hose break‑safety device, or HBS, is a safety component in liquefied gas systems. Its main function: to automatically interrupt the gas flow if a serious leak occurs in a hose line. This prevents large amounts of liquefied gas from escaping uncontrollably—an important protection against fire and explosion hazards.
The HBS is used in many areas: from a gas barbecue on the patio to applications while camping in a motorhome or caravan, to heating appliances or commercial liquefied gas systems. Its principle is similar to that of an “aquastop” in washing machines: should a leak occur, the device immediately reacts and shuts off the flow.
The HBS may either be installed as a separate component directly between the pressure regulator and the hose, or already integrated into the pressure regulator. Which design is used depends on the specific system and requirements.
Inside a hose break‑safety device is a special mechanism that responds to gas flow. Under normal conditions, gas flows through the device at a constant rate intended for the system. If the flow suddenly increases significantly—e.g. due to a rupture or separation of the hose—the HBS detects this abnormal rate and activates.
The heart of the device is a closing cone or valve pin that is propelled by the high gas flow. Within seconds, it completely blocks the passage. Gas flow stops, and no more liquefied gas can escape uncontrollably.
There are two versions of HBS:
Each HBS is designed to trigger at a specific response point, based on the nominal flow rate of the connected liquefied gas system. If this is exceeded by a defined percentage, the HBS activates and interrupts the gas flow.
A typical example: for small‑cylinder systems—such as those used for gas barbecues, heaters or parasols—the standard HBS is rated at 1.5 kg of liquefied gas per hour at an outlet pressure of 50 mbar. If a leak develops in the hose and actual flow exceeds this nominal rate by around 10%, the valve shuts off. This prevents large quantities of gas from escaping in a short time.
Whether installed as a standalone component or integrated into the regulator, the activation mechanism remains the same: it responds to unusually high flow rates and stops the gas supply within seconds.
The hose break‑safety device is usually installed directly at the outlet of the pressure regulator. From there, the hose leads to the appliance—e.g. to a barbecue, heater or cooker. Positioned there, the HBS monitors the entire gas flow in the hose line and can react immediately in the event of a defect.
There are two common designs:
Typical application areas:
In all cases, installation should be carried out by a qualified person according to the supplied installation and operating instructions to ensure tightness and functional safety.
Advantages:
Safety notes:
The hose break‑safety device is a small but highly effective safety component in any liquefied gas system. It prevents uncontrolled gas leakage in the event of hose failure—protecting people, vehicles, buildings and appliances from accidents. Depending on the application area, different regulations apply:
At home, on the road or in commercial use—the hose break‑safety device provides critical protection everywhere and should never be omitted from any system.
This blog will never ask members of the public or unqualified persons to make changes to or fiddle around with technical systems themselves.
In accordance with the Industrial Safety Regulation (BetrSichV), a qualified person must take care of a system which requires monitoring.
A qualified person is someone who has the specific specialist knowledge required. This knowledge is gained by way of a professional apprenticeship, corresponding professional experience or current occupational activity.
Please note that the texts are based on information, regulations and standards for Germany. Please always check the rules and regulations in the relevant country of destination and consult specialists if necessary.
