EV, with air on the upper side of a rubber diaphragm.
Also - that pinkish circulator pump should be dead horizontal, because they don't have endthrust bearings. Doesn't appear to be.
If you look at the far right of the supply on that pic you'll see the stop tapand there should be an isolating valve on the inlet
The only one, Red, 12L, that I removed from a oil fired boiler just had a bladder that was sandwiched with a flange at the water end, it doesn't seem a great arrangement as the bladder is then pushed back (crushed?) against the water end on precharging and will only be partially refilled with 2.4L of water with a 1.5Bar filling pressure (1.0Bar precharge pressure), I'm surprised they have a reasonably long life but obviously if inserted the "right" way, from the air end (if it was possible) the the EV might corrode fairly rapidly as water would now be in contact with the mild steel interior, instead of nitrogen and eventually air.The vessel you refer to is only used on heating systems. Vessel in question has a bladder which is surrounded by a cushion of air ( expansion medium)
Vessel used on a heating system cannot/ should not be used on an invented cylinder.The only one, Red, 12L, that I removed from a oil fired boiler just had a bladder that was sandwiched with a flange at the water end, it doesn't seem a great arrangement as the bladder is then pushed back (crushed?) against the water end on precharging and will only be partially refilled with 2.4L of water with a 1.5Bar filling pressure (1.0Bar precharge pressure), I'm surprised they have a reasonably long life but obviously if inserted the "right" way, from the air end (if it was possible) the the EV might corrode fairly rapidly as water would now be in contact with the mild steel interior, instead of nitrogen and eventually air.
I have seen photos of others (white & red?) where a diaphragm is sandwiched between two "halves" of the EV, seems a better arrangement but maybe only used on the larger EVs?.
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