[TheForge] Hydraulic Press

[David E. Smucker]

James is correct.

In my old day job (ALCOA) all of our large extrusion presses and large 
forging press were water hydraulics -- at high pressures.  Some small units 
were on Pydraul (fire proof hydraulic fluid) -- which caused great 
enviromental problems because of PCB's -- don't want to go there.  Even with 
water hydraulics at 5000 psi we had some very serious safety issues because 
of piping failure in large diameter pipe.  (At least one death I remember 
with this type of failure.)  This equipment was really really big.  The big 
press at the Cleveland Works is a 50,000 ton closed die forging press. 
There is a smaller 35,000 ton unit there too.   (I was a rolling mill guy, 
not a extrusion or forging but we had the big plate mill at 20,000,000 
pounds seperating force and 220 inch plate width. -- Davenport, IA Works.)

None of this applies to blacksmithing presses except that there are some 
similar risks and one of the ones that I have always been most concerned 
about is fire.  Even if it doesn't get you it may burn your shop down.  That 
is why I like designs where all of the hydraulics, including the cylinder is 
below the hot metal.  (Can be either a pull down, or push up design.)  Then 
with some sheet metal work you can get all of the hoses and or lines 
enclosed so that if you have a leak (and you will) you just get a mess.

Dave Smucker

--------------------------------------------------
From: "James Binnion" <jbin at well.com>
Sent: Saturday, March 19, 2011 6:22 PM
To: "Blacksmithing List Sponsored by ABANA" <theforge at mailman.qth.net>
Subject: Re: [TheForge] Hydraulic Press

> Some of the big extrusion presses use water as the working fluid. There 
> are a bunch of problems that come from a corrosive hydraulic media but 
> fire is not a problem :-)
> The other thing that the big presses have is lots of pump capacity. The 
> "little" press I worked with, a 750 ton had 500 HP  pump motors the big 
> 3500 ton press had a handful of  300 or 500 hp motors. Obviously  this 
> kind of power is only available on industrial sites.
>
> On Mar 19, 2011, at 1:46 PM, David E. Smucker wrote:
>
>> The second great risk is of fire from a failure in the hydraulic hose or
>> pipe system on a press.  With HOT metal we always have present a way to
>> light off the oil mist from a leak or hose break.
>
> James Binnion
> jbin at well.com
>
>
>
> ______________________________________________________________
> TheForge mailing list
> Home: http://mailman.qth.net/mailman/listinfo/theforge
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:TheForge at mailman.qth.net
>
> TheForge mail list group photo site is
> http://www.photoworks.com
> Login: blacksmithblacksmith at hotmail.com
> Password: anvil
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>