propane operates at 37 mb and butane at 28 mb but if your caravan is a tourer built after i think 2004 and has a bulkhead regulator they will probably work at 30mb and will do for both propane and butane but you will have to change the pig tails (the hose from the bottle to the reg) they use them because bottles in Europe all come with different fittings, but if your caravan is a static with a bottle outside you will have to change the regulator and remember to install another vent ,if being used all winter by you and your family i would really get a gas safe engineer to look at it and get