Well I had a G-Max valve completely blow off and flood a basement bathroom on a 8 year old Toto toilet on Christmas Eve. Damage was not to bad due to my son being close by when it happened so he shut off the water quickly. I recently discovered that the water pressure in my house is a nominal 105 psi and I don't have a PRV or and expansion tank so I can only assume the pressure must have increased and it broke the plastic tabs that hold the valve portion on to the part that is bolted to the ceramic tank. The highest I have measured the pressure is 115 psi but it is possible that it went higher. On my "To Do" list was to add the PRV and expansion tank. Looks like that will be a New Year weekend project. I was surprised that this would happen so I thought I would pass this along to those with high pressure in their homes.
Gary
Gary