Brand new caravans or motorhomes are now always fitted with an LPG system with a working pressure of 30 mbar (millibars). This is regulated in a standard which is binding for EU member states – EN 1949. Accordingly, most gas equipment for leisure vehicles, such as boilers, gas grills, stoves or heating systems, are also designed for the nominal pressure of 30 mbar. But what if the gas system is still running with 50 mbar?
This is commonplace among older leisure vehicles. Back then, the systems were designed for 50 mbar; EN 1949 was the first regulation to standardise the different working pressures across Europe. The older 50 mbar systems still have ‘grandfathering’ protection, which means they don’t have to be converted to 30 mbar. However: The absolute majority of gas equipment still only works with the lower working pressure. So what can campers do?
Pre-pressure regulator for 30 mbar
To operate a 30 mbar fridge via the 50 mbar gas system, for example, you merely need an additional pressure regulator in the piping of the caravan or motor caravan. This regulator reduces the incoming pressure of 50 mbar to an outgoing value of 30.
According to DVGW worksheet G 607, these must “be installed in an easily accessible place directly before the gas equipment or directly after the distributor valve in the feed line of this device”. In any case, the pre-pressure regulator is always fitted downstream of the actual pressure regulator. And: When the pre-pressure regulator is installed within a vehicle, the specialist fitter must add a discharge line leading outdoors via the corresponding nozzle of the fitting.
Restriction of use
On the subject of 30 and/or 50 mbar, you must be aware that when outdoors, only gas equipment with a nominal pressure of 50 mbar may be operated. Outdoor gas equipment for leisure vehicles are an exception in the technical regulations. If you supply gas equipment via the LPG systems of caravans etc., you may also use 30 mbar end devices.
We are often asked the question: If you can regulate the pressure from 50 to 30 mbar, does this work the other way around as well? A clear answer: No, because once the pressure is reduced, it can’t be brought back up to a higher level.
Note about output
Finally, a note if you use the pre-pressure regulator: This “only” has a maximum output of 0.8 kg/h. Some pressure regulators that are directly on the bottle or two-bottle systems achieve an output of 1.5 kg/h. If you want to supply gas devices with liquid gas via the pre-pressure regulator, you should ensure that the devices connected do not consume more than 0.8 kg/h. The 0.8 kg/h correspond to around 10 kW (kilowatts). You can find more information about the conversion in this article: