Excess flow valve

The excess flow valves are part of the house installation and are usually installed directly behind the service entry. They independently shut off the gas supply when the volume flow is unnaturally high. In this way, gas accidents due to manipulation or defective gas lines can be reliably prevented. The excess flow valve is sometimes also referred to as a gas throttle stop.

https://www.sbz-monteur.de/allgemein/gs-wie-grosse-sicherheit (in German)

The excess flow valve is always created on the house connection line (reference to Rules). In some cases, the excess flow valves are also installed outside the building in a manhole (see graphic > dotted "GS"). Currently, this object is used in many plants to indicate that a EFW is installed. Currently, the excess flow valves were recorded on the house connection line outside the building (not correct position). As a rule, the line was not split at this point. The excess flow valve is a safety-relevant and verifiable component in the gas network.