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trailerrails
07-07-2009, 01:53 PM
Can anyone tell me about this air cylinder? I know it is 2" bore and a 15.5" stroke. I want to find out what the operating pressure is and what it's capacity is at that pressure. Some of the numbers on the label are: ISO 6431; NFE 49003; VDMA 24042; and ED6.22.115.N
I tried Google and found the company but no info on air cylinders on their site.

Muzikman
07-07-2009, 02:04 PM
Nevermind...wrong kind of air cylinder.





Can anyone tell me about this air cylinder? I know it is 2" bore and a 15.5" stroke. I want to find out what the operating pressure is and what it's capacity is at that pressure. Some of the numbers on the label are: ISO 6431; NFE 49003; VDMA 24042; and ED6.22.115.N
I tried Google and found the company but no info on air cylinders on their site.

trailerrails
07-07-2009, 02:12 PM
http://img.photobucket.com/albums/v469/trailerrails/jkhfuiytf768.jpghttp://www.pgh-offroad.com/forum/%5BIMG%5Dhttp://img.photobucket.com/albums/v469/trailerrails/jkhfuiytf768.jpg%5B/IMG%5D

DeathBlade556
07-07-2009, 05:47 PM
Looking through my tech books for a cylinder of similar size( 2" bore x 12" stroke) it probably is rated for 280lbs of force at 100psi with a probable 200 psi max.
What are you using it for?

trailerrails
07-07-2009, 07:01 PM
Those were the numbers I was guessing at. Surface area of the piston times the psi. I just wanted to make sure I was on the right track.
I want to build am air operated motorcycle lift. One bike weighs in the 200# ball park while the other is in the 350# ball park. I think if I build it to lift 500#, I think I would be pretty safe. What sucks is if I build it for that weight then I would only be able to move about 8" or so. Right? I was hoping to get about 30" of lift out of it. To do that I would need a large diameter piston or a higher pressure air system.

DMG
07-07-2009, 10:13 PM
Gabe, you are the mad scientist but wouldn't it be something like 314 lbs of force at 100 psi? Probably not enough either way, though.

trailerrails
07-08-2009, 09:58 AM
Gabe, you are the mad scientist but wouldn't it be something like 314 lbs of force at 100 psi? Probably not enough either way, though.

You are right, radius x pi x psi.

DeathBlade556
07-08-2009, 02:03 PM
I just check my McMaster catalog and they list 290 pounds of force for a 2" x 8" and 459 pounds for a 2 1/2" x 6" cylinder.http://www.mcmaster.com/#6498k413/=2npo3i

trailerrails
07-08-2009, 03:53 PM
I just check my McMaster catalog and they list 290 pounds of force for a 2" x 8" and 459 pounds for a 2 1/2" x 6" cylinder.http://www.mcmaster.com/#6498k413/=2npo3i


That is odd, I wonder how they are calculating that. I might just hook up 2 of these air cylinders to get the job done. I have a line on them for cheep.

Krod
07-08-2009, 04:19 PM
I just check my McMaster catalog and they list 290 pounds of force for a 2" x 8" and 459 pounds for a 2 1/2" x 6" cylinder.http://www.mcmaster.com/#6498k413/=2npo3i

You guys have the formula right, but you're looking at double acting cylinders there, so you need to factor in the loss of surface area on the piston due to the rod.

http://www.mcmaster.com/catalog/115/gfx/large/doubleal.gif

For single acting 2" Bore extending: (Pressure)*(Area of Piston) = Fapplied
For single acting 2" Bore retracting (or double acting cylinders): (Pressure)*(Area of Piston - Area of rod) = Fapplied

Extending:
100psi * (1.00^2)(3.14) = 314 lb

Retracting:
100psi * (3.14 - unknown rod area) = 290 lb

Running the math backwards gives us a rod diameter...
290lb / 100psi = (3.14 - unknown rod area)
2.9sq.in = 3.14sq.in - unknown rod area)

unknown rod area = 0.24 sq.in

so the rod diameter is .553 inches



So for the cylinder you're looking at on MMC, the force is:

100psi * (3.14 - 0.24) = 290 lb as rated









If you're just looking to use the cylinder you have to apply force as it is extending, then you don't need to worry about the rod area, just the bore diameter (which will let you calculate the surface area of the piston)

trailerrails
07-08-2009, 05:53 PM
Wow, that is the math I was looking for.

What confuses me is how they get 459#'s for a 2.5" bore.

Krod
07-08-2009, 06:02 PM
Wow, that is the math I was looking for.
What confuses me is how they get 459#'s for a 2.5" bore.

Those numbers are for a Double acting cylinder. Gotta subtract the rod area from the p/A equation to get the force in a pull. MMC probably just rates their double acting at their lowest force for a given PSI (which would be the pulling force) :thumbsup:

A 2.5" bore @ 100psi = 490 lb if you're extending

Krod
07-08-2009, 06:35 PM
Some searching led me to a rating of 10 Bar, so 147psi. ~ 150 psi max rated pressure.

Assuming you want to run this on normal 90psi "shop air", you could probably expect about 280 lbs out of that cylinder. 100 psi gets you 314 lbs like Dave posted earlier (assuming you use it to apply force in the extending direction).