Improving hydraulic bottle jack

[Hans Pearson]

I used a 12 tonne jack (inverted) in my hydraulic press. This means that under the full allowed load the pressure in the cylinder would be in the region of 11 200 psi. I changed the pump to an external pump with a slightly larger area and under test could only push about 6.5 tons which was still quite ample for normal use for me. Looking at jacks in general, the pump area on all jacks seems to remain constant, the piston size is changed to allow for higher loads, and subsequently longer pumping times/more strokes to achieve the same lift distance.

[Hans Pearson]

Tony, I have just been over my figures for my press pressure in my 12 tonne press. The piston diameter is 1.73" which gives an area of 2.35 Sq. In. 12 Metric tonnes is near enough 24300 lbs. Divide the area into that and it gives a slightly revised pressure of 10340 psi to obtain 12 tonne lift.

[tonyfoale]

Tony, I have just been over my figures for my press pressure in my 12 tonne press. The piston diameter is 1.73" which gives an area of 2.35 Sq. In. 12 Metric tonnes is near enough 24300 lbs. Divide the area into that and it gives a slightly revised pressure of 10340 psi to obtain 12 tonne lift.

Hans, You must have seen a post that I made which I deleted the contents of, and which is not being shown now. I apologise. I made an error and as soon as I realised it I went and deleted the contents hoping that nobody had seen it. Your numbers are fine, mine were not.