re. Sam Evans - I must disagree with your comment the the tin cans are 'inherently' stronger than Roundhouse gas tanks. I have been told that the end 'valve' blows out at two / three hundred psi. The figures I quoted were given in conversation with RH & they apply both to RH cylindrical & rectangular tanks - they have made them that way. I think Clark got it right - it is a butt covering exercise. A wise precaution in a country where mishaps are never due to individual stupidity but always to manufacturers, the previous government, or both. Art Walker, Guildford.
