If you worry about the risk posed by gas leaks, an excess flow valve is an excellent investment. This Hilo Excess Flow Valve, sometimes also referred to as a “HiLo Adaptor Multi-Purpose Fitting (Propane)”, has been designed especially for motorhomes & caravans.
In the event of an uncontrolled release of gas it will close immediately, preventing any dangerous build-up in your caravan or motorhome. (You can reopen it with a pushbutton once you've sorted out the leak.) The unit incorporates a pressure meter, and the POL fitting will work with any UK propane cylinder.