I'm in the market for a 30 ton cylinder to go with my enerpac air
driven pump.

I seen this offer:
http://www.ebay.com/itm/Enerpac-RR-3...item4d00a32783

didn't know of two way for enerpac. Then this thought occurred to me.
Would it work to use the pump on one side and then an air line on the
other to make it retract?

Karl

Karl Townsend fired this volley in
:

didn't know of two way for enerpac. Then this thought occurred to me.
Would it work to use the pump on one side and then an air line on the
other to make it retract?


Karl, probably not. Those cylinders have a HUGE amount of "stiction"
between the piston seals and the walls. It often takes 200-300psi just
to get them moving at all.

When Enerpak cylinders are double-acting, it usually involves valving, so
the user can push or pull with the same cylinder.

Some of the portable gas-powered pumps have 4-way valves on them, though.

LLoyd

On Fri, 27 Apr 2012 06:45:35 -0500, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

Karl Townsend fired this volley in
:

didn't know of two way for enerpac. Then this thought occurred to me.
Would it work to use the pump on one side and then an air line on the
other to make it retract?


Karl, probably not. Those cylinders have a HUGE amount of "stiction"
between the piston seals and the walls. It often takes 200-300psi just
to get them moving at all.

When Enerpak cylinders are double-acting, it usually involves valving, so
the user can push or pull with the same cylinder.

Some of the portable gas-powered pumps have 4-way valves on them, though.

LLoyd

OK, I'll keep watching. All my 10 ton and the very short 30 ton have
spring return inside.

Karl

"Karl Townsend" wrote in message ...
On Fri, 27 Apr 2012 06:45:35 -0500, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

Karl Townsend fired this volley in
m:

didn't know of two way for enerpac. Then this thought occurred to me.
Would it work to use the pump on one side and then an air line on the
other to make it retract?


Karl, probably not. Those cylinders have a HUGE amount of "stiction"
between the piston seals and the walls. It often takes 200-300psi just
to get them moving at all.

When Enerpak cylinders are double-acting, it usually involves valving, so
the user can push or pull with the same cylinder.

Some of the portable gas-powered pumps have 4-way valves on them, though.

LLoyd

OK, I'll keep watching. All my 10 ton and the very short 30 ton have
spring return inside.


I've seen quite a few H frame presses with external spring(s)...