[hypoxia]

Would you guys correct me if I am wrong. I am imagining the accumulator to conceptually much like a pressure tank on a well pump system. A steel tank with an internal bladder. The bladder is precharged to an adjustable level. Let’s say the pre charge is 50 psi. When hooked up to a water pump, when the water pressure coming from the pump exceeds 50 psi, the bladder starts to compress and continues to compress until the cut off pressure of the water pump. So if the cut off pressure of the water pump is 100, then IF you measured the bladder pressure it too would be 100 psi.

My point being, that although the accumulator starts off at it’s precharge pressure, as soon as the hydraulic side is pressurized above it’s 10 bar (147 psi) then the pressure in the accumulator will be whatever the hydraulic pressure is.

If my thinking is correct, then the N2 pressure sensor will read whatever the hydraulic mule charges the system to. And if Newell is charging to 275, the sensor in the picture show 230 as the upper limit I think. Just wondering out loud if overpressuring the sensor is the cause of failure.

I think your theory is correct. This is a sealed system. There is no pump or compressor. I think the only purpose of the accumulator is to absorb any shocks and keep the system stable. I am puzzled as to increasing the  pressure and what that accomplishes?  MCI had a recall on their buses, and it was basically just an inspection and using the same original pressures.  I am certain they all know more than I do!  If I would have read your post earlier, I would have purchased the sensing switch that had the higher pressures.