i'm rebuilding my jack pres. it will have a new frame and i will mount a gauge on the hidraulic jack.
I'm doing some calculation to be sure the 5T jack is enough for my projects.
The most high pressure required for project i've seen is 7500PSI (for whistles) so i want to be sure that my press will be able to reach this value for tubes until 2,5cm ID.
as i'm more pratical with metrical system i will use Kg, square cm (or cm2), KSC (kilogram per square centimeter) , MPa (Mega-Pascal ), Square inch (sq-i)
You can use this table for conversions: http://en.wikipedia.org/wiki/Pressure
1 PSI= 0,06895 bar = 0,00689 MPa =0,07031 KSC
7500 PSI are equivalent to about 527 KSC = 517 bar = 51,71MPa [i have to reach this!]
The diameter of the larger *visible* part of the piston my jack is about 28mm, i suppose that when i will un-mount the jack to apply the gauge (as in this page: http://www.skylighte...ocket-press.asp) it will have a max diameter of 35mm (where oil will apply the force)...
with 35mm diameter i have an Area of 11,34cm2 (1,76sq-i) [bottom piston area]
now, if i want press a whistle of 2,5 cm ID i should apply a force over an Area=Pi * 1,25 * 1,25= 4,91 cm2 (0,75 square inch) [ram area]
To have 527KSC on 4,91cm2 i need 527 * 4,91 = 2587Kg (about 2,5Ton - 5703Pounds) [Force needed in the jack]
This mean that my 5Ton jack is enugh for this job also if the label lie of 1 Ton. (right?)
Now i calculate what i should read on the gauge to ensure i'm applying 7500PSI (or 527KSC) on the whistle comp (in the 2,5 cm ID tube)
2587Kg=5703Pounds, this mean i should apply 5703Pounds over the entire bottom piston area (see up for measures)
5703Pounds / 1,75sq-i= 3259 PSI (224,7 Bar | 22,47 MPa ) [Correct reading on the gauge to have 7500psi in 2,5cm ID tubes]
As the ratio between RAM diameter and piston bottom diameter is 0,75sq-i/1,75sq-i = 0,43 i can say that when i need X PSI of pressure on the composition in a tube 2,5cm ID i need to read on the gauge Y = X * 0,43 [generic formula to have correct read on the gauge in 2,5cm ID tubes]
A most generic formula to obtain the PSI value Y to read on the Gauge for
- tube of ID or Ram diameter (inches) = Z
- bottom piston diameter (inches) = W
- Needed PSI inside the tube = X
Y = X * ( Z^2 / W^2 )
Do you think is this all correct?
Edited by pyrosailor99, 17 October 2012 - 10:02 AM.