This is health&safety related question that came out of a discussion I had with a friend. I sometimes keep a large (L sized) helium cylinder in my lab. It is pressurized to 200 Bar and equipped with a standard regulator. Now, the question is what would happen if it fell over and the regulator was damaged? I am fully aware of what would happen if it was actually knocked off and the gas could escape (we have all heard stories about cylinders flying through walls), but presumably the regulator/cylinder is designed to minimize the risk of that happening? Is the regulator designed in such a way that it should break in a way that blocks the gas flow? I haven't been able to find anything about this online (except the usual "don't let it happen" warnings) I should mention that both the cylinder and regulator are approved etc.