pneumatic/hydraulic.. what size cylinder do I need?

[ndemge]

The task, pushing 2" wood plugs into 2" HDPE pipe<br /><br />Current method, 3 whacks with a 6lb sledge hammer<br />I did 1,000 in 2 days last year and couldn't use my hand for a week.<br /><br />I've looked on ebay for pneumatic cylinders, It looks like I could get a pneumatic setup pretty cheap and build a semi-automatic pipe plugger, but the question of how strong a cylyder ??<br /><br />What's the formula? working with 90-120psi, what size bore give x force?

 

[gspig]

Re: pneumatic/hydraulic.. what size cylinder do I need?

You need to find out the psi force you need to set the plugs. Cylinder force is supply pressure(90-120 psi) times the surface area of the piston's plunger(bore). area of a circle X pressure gives you the force in psi the cylinder will exert. Also consider that the smaller the bore cylinder you can use, the faster you can move that cylinder.

 

[Paul Moir]

Re: pneumatic/hydraulic.. what size cylinder do I need?

Couldn't be simpler. PSI is pounds per square inch, so all you need to know is how many square inches the pressure is acting on to know pounds of force. Since the piston is a circle, and all you know is the bore diameter, you'll have to calculate the area of the piston.<br /><br />Area in sq.inches = (1/2 diameter)² x pi or <br /><br />Area in sq.inches = (1/2 diameter) x (1/2 diameter) x pi <br /><br />So say you've got a cylinder with a 1.5" bore (the bore is the same size as the piston):<br /><br />Area = (1/2 x 1.5)² x 3.14<br />Area = 1.77 sq inches<br />Then just multiply that by your PSI (say 90):<br />Pounds of force = 1.77 x 90<br />Pounds of force = 159 lbs.<br /><br />I don't know if that's enough to get your plugs in. You might want to experiment with the required weight a bit.<br /><br />Hope this explains it!<br /><br />EDIT: Gspig beat me to it!<br /><br />EDIT2: hydraulics works basically the same way except you get to use a much higher pressure (3000 or more PSI sometimes)

 

[ndemge]

Re: pneumatic/hydraulic.. what size cylinder do I need?

hm... anyone have an adjustable press I can give ya a sample to see how much it takes?

 

[Paul Moir]

Re: pneumatic/hydraulic.. what size cylinder do I need?

Would pushing them in with or on a bathroom scale work?

 

[chuckz]

Re: pneumatic/hydraulic.. what size cylinder do I need?

I could do it with a compression tester at work. I'd have to charge for the service though. If you're interested e-mail me at chuck@nypts.com.

 

[ndemge]

Re: pneumatic/hydraulic.. what size cylinder do I need?

thanks, email on the way

 

[SS MAYFLOAT]

Re: pneumatic/hydraulic.. what size cylinder do I need?

ndemge, I have some pnuematic cylinders that are mostly gunked up with grill grease. They won't meet standards for my stores. I'm a pack rat and just hate thrown things away. The bore is 2" with a 7" stroke. 1/4" npt ports, 1/2" threaded piston, and case end is a casted eyelet. I made a can smasher with one using about 80 to 120 psi. It would flatten a soda/beer can down to about 3/16 inch thick. If your interested in one, shoot me mail. ssmayfloat@neo.rr.com<br /><br />I will even clean off the thick coating of burger grease for ya, but you will need to take it apart and degrease the inside.

 

[pjc]

Re: pneumatic/hydraulic.. what size cylinder do I need?

If you care to use hydraulic on the cheap use a one ton bottle jack. Fabricate a frame of sorts to fixture pipe and mount jack to same. Google H-frame press or similar for ideas. Be mindful that a press as described may be painfully slow compared to the hammer method.<br /><br />Also, the impact force (6# hammer) you currently apply to seat these plugs is a complex calculation. Difficult to measure/calculate the force you are imparting to thus learn what pneumatic or hydraulic force you need.