Hi all :   I need some help in pressing the steering clutches on. I have a 10 ton porta power and a 20 ton hollow jack. How do I convert the porta power PSI to the tons of the jack? I have watched PNW Hillbilly do it on youtube but still not sure how to read the numbers. I have a D4 7U and believe pressing it back together pressure is 10-12 tons. This may be a question for Matt  PNW Hillbilly   THANK YOU!

This info may provide some guidance... From the enerpac web site:
Calculating Hydraulic Ram Pressure

The amount of force a hydraulic cylinder can generate is equal to the hydraulic pressure times the “ effective area “ of the cylinder.

The RCH 202 hollow ram 20 ton cylinder has an effective area of 4.73 inches… thus: 4000 psi x’s 4.73 = 18,920 psi or 9.46 tons of force.
5000 psi x’s 4.73 = 23,650 psi or 11.82 tons of force.


The RCS502 solid 50 ton ram has an effective area of 9.62 inches… thus:
2000 psi x’s 9.62 =19240 psi or 9.62 tons of force.
2500 psi x’s 9.62 = 24050 psi or 12.02 tons of force.
3000 psi x’s 9.62 = 28860 psi or 14.43 tons of force.


From the Enerpac web site 8-24-14

Thank You bcwayne for the info. It doesnt seem too hard to do the math. I was looking for that formula,I should have gone to Enerpac.I wanted to make sure Im applying the correct pressures so I dont crack the casting.

A lot of (cheap) rams out there don't specify the effective area/diameter and you are just supposed to assume that if it's a 20t ram, it will give you 20t at 10k PSI, but the reality is that is sometimes not the case. If you are going to cheap out on a ram and hydraulic pump like I did, just make sure you find one with a listed effective area/diameter (or measure it yourself) and have a good quality pressure gauge on your pump.

Good luck on your clutches!

Hey Hillbilly Thank You ! I have been watching all those great Youtube videos on your D4 7U restoration, GREAT JOB! Your videos have helped me to do my 1953 D4 7U renovation. This is my first Cat so between you and all the info from ACMOC the project is getting done.Good luck on your crane project looks like a big project.

most modern portapower gear is made to work at 10 thousand psi. so when you know the piston area you can calculate the force for a given pressure.

i have gotten portapower gear from www.hydraulic.online
they are a australian company but they ship internationally and sell at wholesale prices.

Hi Everyone,
Please do not forget when calculating the pressures of any cylinder - you must subtract the area of the rod if you are calculating pressure (force) on that end of the piston (stroke).
A cylinder will not produce as much pressure (output force) when the fluid/air is applied to the rod end. Generally, given the same flow, it will also react faster on the rod end of the stroke.
(what I am trying to state - larger the area, greater the force, the rod takes up space, thus reducing the effective area of the piston)

Good thing to consider - like a chain - everything is only as strong as the weakest link.

CTS

Hi, cts.
Kwestyun: If every link inna chain is supposed to be the same strength, HOW does the chain know which one to break????????

Or, to put it another way, HOW does the weakest link know that it is the weakest and that it should be the one to break??????

A kew-ree-yuss mind would like to know..

Just my 0.02.

Deas,
That is easy to determine and an "Ol Dozer Operator" should have that all figured out.
Put it to the test, if it does the job, then there is no weakest link!
Now please tell us your story of your test methods, surely, you have proofed a chain or two.

Tell us how you kept those chains from breaking links when you were "chaining" those forests. Big tractors pulling against each other, must be a test!
CTS