What Hyd cylinder to use?

[akpilot]

I'm thinking about building one of these post pounders, my question is there is only one hyd line to the pounder cylinder, so does that mean it is a single acting hyd ram? If I already had a Double acting ram and I only used one side and looped the other side would it still work the same?

 

[J_J]

If the cyl has a single port, it is a SA cyl. It will have a breather port somewhere.

A DA cyl can be used as an SA cyl. Insert a breather plug in the other port.

What do you mean by looped?

 

[akpilot]

Thanks for the info J-J, I'll look for a breather plug. "Looped" my be the wrong term, the valve I have is ment for a DA cyl, if I set this up as a SA cyl then if the valve is pulled in the wrong direction!..... I didn't want it to "dead head" if I looped that side back to the return then "dead heading" wouldn't be possible, does that sound reasonable?

 

[kennyd]

I don't see how a regular cylinder will work well, the fluid needs to escape the cylinder very rapidly to allow the weight to drop fast. The Shaver drivers have custom made cylinders and require special plumbing to the tank to allow for this.

That is unless I am mis-understanding how this one works.

 

[kennyd]

Thanks for the info J-J, I'll look for a breather plug. "Looped" my be the wrong term, the valve I have is ment for a DA cyl, if I set this up as a SA cyl then if the valve is pulled in the wrong direction!..... I didn't want it to "dead head" if I looped that side back to the return then "dead heading" wouldn't be possible, does that sound reasonable?

The system would only be deadheaded for a few seconds, thats what the relief valve is for. You can however plumb the spare port (on your remote) to the tank if it really bothers you.

 

[J_J]

Those post pounder cyl only have about a 1 in rod , but very long.

Hydraulic Requirements 3 - 4 GPM at 1500 PSI

3/4 in return hose directly to tank.

If you were to use a Prince DA valve or similar valve, Prince says to use the B work port and plug the A port.

One TBN guy, said he was using a DA cyl as an SA cyl, but hyd fluid was coming out the other port/vent and messing things up. What was happening was the piston seals were leaking and the fluid has to have somewhere to go. So someone told him to run a hose from the vent port to tank, which you can do, but he should replace the seals in the cyl.

 

[Oliver1655]

Consider checking your operators manual on connecting a single acting cylinder. Some tractors like my Oliver require you to adjust a flow diverter to allow the cylinder ram to return. Other may require it to be attached to a specific port. (Rod vs base, "A" vs "B") Another consideration in the air moving in & out of the vent & over time with corrode/pit the cylinder wall. Periodicly adding a small amount of hydraulic fluid through the vent location may slow down the corrosion. This is the reason most farmers avoid single acting cylinders when possible.