This safety valve is a real ray of light in comparison to most other available on the market heater safety valves. The ability to simply unscrew the top part including the diaphragm and seal with calcification or other contamination and to clean, I would call quality engineering. Also, the required heating at each maintenance function test of the safety valves is thus better feasible. The membrane can be long-lasting and flushing as it can be possible by the many other models. All-round excellence. This also applies for the model 651mWNK (10 bar), which is available by Esska.