Adrian wrote: snipped: > As substantiation that this happens, I've been using the same > (no-diaphragm) accumulator for nearly twenty years without draining > water from it, and it is still working fine.
In an effort to soften the shift change on my PRM 500 gearbox on Albion I experimented with an accumulator chamber with no diaphragm to soften the pressure rise and found that the accumulator rapidly filled with oil, displacing the air contained within, and negating any effect from the air cushion. I admit that the pressures involved are much higher with the hydraulics on the gearbox than a water system but it does seem to illustrate the point that was made that you can't always rely on the air remaining at the top of an accumulator with no diaphragm after a period of use. When I added a proper diaphragm-style accumulator the springing effect was maintained, as you would expect. Roger
