How does a hydraulic ram make 180000 tons of force

[woodlandfarms]

Watching a video in the welding section (a video on how pressure tanks are made) and they use a ram that puts out amazing pressure. Not to be ignorant, but what kind of pump builds that kind of pressure and what kind of seals hold up under that pressure, heck, what kind of hoses survive that pressure. I must be missing something.

 

[davesl708]

Hydraulic forces are a function the size of the fluid entering the cylinder and the size of the cylinder in square inches. YouTube has good videos on the process. No seals are used at those pressures. It is the close fit of the ram an cylinder that contains the pressure.

 

[Ruger761]

I have a ram at work that I made for testing off shore equipment. It puts out 1.3M lbs of force. Has 169 in^2 piston at 7700 psi. Like Daves said all about the size of the cylinder and the pressure. This ram actually has very large O-rings for seals. Pump for it actually goes to 17,000 psi. Hoses are good to 15,000 psi. Not your standard off the shelf system by no means and doesn't move very quickly either.

 

[bigdeano]

When I watched the video they said 800 tons. Still a lot though.

 

[Leejohn]

You could do it with 2000psi, but I would hate to guess what size the bore would have to be.

 

[LD1]

Take the bore size of the cylinder.

Pi times r squared times hydraulic pressure (psi) equals force.

180,000t is 360,000,000 pounds of force.

With a 5000psi system, you would need the bore to have 72000 sq inches. Or a diameter of about 300" (25')

A little beyond belief... I think you tons and pounds confused or something, but certainly doable.

As said, seals contain the pressure. Which don't have to be any higher than a normal system. Size gets you the tonnage.

At work, we have a hydraulic press that has a 14" bore cylinder with a 120" stroke for making the halves of aluminum propane cylinders. (Forklift cylinders). At about 2600psi it makes around 200t. There are 3 pumps each driven by a 150hp motor. Each in the 70gpm range. So over 200 gpm flow. 2500 gallon resivoir and high pressure fed through 4" main lines.

Bigger is certainly not hard to imagine. Just scale things up. Look at the size of some of the big construction equipment

 

[Texasmark]

You could do it with 2000psi, but I would hate to guess what size the bore would have to be.

Do the math. Piston area is ½ the diameter squared (d/2 x d/2) x pi (22/7 or 3.1417XXXXXXX) x pressure in pounds per square inch yields pounds of force.

180,000 tons is 3.6x exp8 (natural logs) = 2500 psig (for a number for pressure in psig) x area of piston.

Transposing, area of piston = 18000 tons/2500 = 1.44 exp5.

Diving by pi 1.44 exp5/3.14 = ½ dia squared (radius squared) = 4.6 exp4 inches (since values are in #/ in squared).

Solving for the diameter in inches = square root of 4.6 exp4 = 2141 x 2 = 4283/12 = a diameter of 35'.

,,,,,,,,nothing else to do this evening :cool2:

 

[CalG]

Do it the other way.

Press 2000# against a very small area and the loading in PSI can be very large indeed. There is reason that fine mechanical watch movements used jewels. HIGH loads on those tiny pivots.

But for the sake of the hydroforming example, The "tonnage" can be high if there are lots of square inches in play.

180,000 tons is a meaningless number. The air we live in exerts that much over any (do the math here) area of the earth's surface.

 

[npalen]

Lets see--180,000 tons of force equals 360 million pounds of force. Thats a lot of cheeseburgers!

 

[SPYDERLK]

Take the bore size of the cylinder.

Pi times r squared times hydraulic pressure (psi) equals force.

180,000t is 360,000,000 pounds of force.

With a 5000psi system, you would need the bore to have 72000 sq inches. Or a diameter of about 300" (25')

A little beyond belief... I think you tons and pounds confused or something, but certainly doable.

As said, seals contain the pressure. Which don't have to be any higher than a normal system. Size gets you the tonnage.

At work, we have a hydraulic press that has a 14" bore cylinder with a 120" stroke for making the halves of aluminum propane cylinders. (Forklift cylinders). At about 2600psi it makes around 200t. There are 3 pumps each driven by a 150hp motor. Each in the 70gpm range. So over 200 gpm flow. 2500 gallon resivoir and high pressure fed through 4" main lines.

Bigger is certainly not hard to imagine. Just scale things up. Look at the size of some of the big construction equipment

Do the math. Piston area is ｽ the diameter squared (d/2 x d/2) x pi (22/7 or 3.1417XXXXXXX) x pressure in pounds per square inch yields pounds of force.

180,000 tons is 3.6x exp8 (natural logs) = 2500 psig (for a number for pressure in psig) x area of piston.

Transposing, area of piston = 18000 tons/2500 = 1.44 exp5.

Diving by pi 1.44 exp5/3.14 = ｽ dia squared (radius squared) = 4.6 exp4 inches (since values are in #/ in squared).

Solving for the diameter in inches = square root of 4.6 exp4 = 2141 x 2 = 4283/12 = a diameter of 35'.

,,,,,,,,nothing else to do this evening :cool2:

Lets see somebody find a cylindrical pressure vessel tens of feet in diameter that will withstand several kpsi internal pressure.