I had one of the new design safety valves sitting on the shelf here and i could hear the faint whisper of steam escaping from my machine that had the original design of safety valve on it, so yesterday i decided to fit the new one

The first thing that is obvious is the anti-tamper wire retainer is no longer present on the new design - the anti-tamper mechanism is a sealed grub screw instead

The next thing you notice is that the nut is machine much higher on the body of the safety valve; this offers the significant benefit of allowing the wrench you are using to remove or fit the safety valve to clear the top of the anti-vac valve that is right alongside the safety valve

Finally, and perhaps most importantly, the new design seals better; my heating element went from a 47 second cycle to a 1 minute 19 second cycle, which is a significant reduction is energy consumption so this valve will quickly pay for itself

If you are working on an LR, which would be unlikely as i think most of them have the new style of safety valve, i recommend removing some of the copper pipes to allow you easier access to swing your wrench