Gallery, Projects and General > How do I??

Any Enerpac Experts or experience on the Forum?

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awemawson:
I'm re-building an EPCO 60 ton 'Garage Press' - I've replaced the double acting piston seal assembly as it was passing oil from one side to the other, but now that's all fixed a fault has developed in the Enerpac Hydraulic power pack.

It's an Enerpac BPE 14485 pump unit, with an Enerpac BVS 4 electrically operated change over valve. Pump will develop up to 10,000 PSI (yes TEN THOUSAND PSI not a typo!). The spool valve is operated by a remote pendant with an 'up' and a 'down' button. Both seem to work fine as I can hear the appropriate pilot valve click when the button is pressed.

When the Down button is operated, oil is fed to the top of the cylinder correctly, and if the press is squashing something pressure builds up and is held when the button is released - this is correct. However when the Up button is pressed it is supposed to release the pressure in the top of the cylinder and introduce oil into the bottom to raise the piston - this is not happening and the press continues to hold pressure for as long as you leave it, even without the pump.

I've been testing at 4000 psi to give my new seals a chance to bed in, and I've just had to release that pressure by cracking a fitting - wasn't too keen on that.

It all looks like the spool for the 'Up' isn't following the pilot but looking at it I'm not sure stripping it and rebuilding is in my competence. Hence seeking advice / contacts / sympathy / replacement.

Here are a few pictures and the details of the spool valve assembly:

smiffy:
In the valve block there must be a pilot operated check valve and this is not getting a signal to open the valve . The  hole in the check valve for the signal is usually very small and become easily blocked .Is there a separate block underneath the operating valve as this is where a check valve should be  Mike

awemawson:
Mike, if you open the .pdf file attached to my first post, there is a full drawing of it.

Some of the caveats in that document are what is making me think twice about opening it up, but I suspect you are right about something being blocked - the whole system has been disturbed so a bit of gunge could easily find it's way where it shouldn't  :bang:

Lew_Merrick_PE:
Andrew -- The valve controlling the cylinder is a 4-Way/3-Position/Blocked Center valve.  The best thing (for you) would be that the Return Line from the "advance ram" plumbing has been clogged or blocked.  The next (as Smiffy wrote) is that the Pilot Actuator has been clogged or blocked.  Otherwise, it is going to me "bubble chasing Heaven."

smiffy:
I had  similar problems on loading bridges at Heathrow ,Turned out that on assembly loctite had been used and as soon as any fittings were disturbed small bits of loctite entered the system and ended up blocking the  pilot valve holes which were only about 25thou in diameter
Parts 51 or 48 might be suspect . All I can see is a parts diagram not  a hydraulic diagram  Mike

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