Samwitch, USIceman; In my previous post when I mentioned the escape line that was blocked with rust and c... A sugestion was made to have the escape lines have a rupture disk after the safety valves, in them to prevent water from reaching the safety valves. Needless to say as it was not a requirment it was not done. I personally would rather have safety valves than rupture disk. One reason being when a rupture disk goes all the charge would be lost. Hopefully with a safety valve after the pressure is relieved the valve would close and the remaining charge would be contained in the pressure vessel. C.D.