Trouble in Hydraulic Piping 1

[ArnoldoGarcia]

Hi
I'm new on this forum.
I have a question.
We have a Hydraulic Press, and the cricuits handle 6000 psi of pressure, we have installed square flange of 6000 psi of rate. But there is a lot o lake, the o-ring were damaged.
What kind of flange we must install?.

Thank you in advance.

Best regards.

 

[eromlignod]

Sounds like you need back-up rings.

http://www.allsealsinc.com/parker/backup rings.pdf

Don
Kansas City

 

[MikeHalloran]

Back-up rings, new seals, careful assembly, no dirt.



Mike Halloran
Pembroke Pines, FL, USA

 

[hydromech]

Depending on the size of the flange and how it seals, I would recommend annealed copper washers.

 

[budt]

Another thing that blows seals at any operating pressure is SHOCK.

Poor Circcit design can allow system Shock to reach 3-5 times system pressure for micro-seconds and can blow seals with regularity.

I've seen seals on 2,000 PSI systems that were eroded from extrusion due to system Shock that was causing instntaneous pressure spikes of 4,000-4,500 PSI every cycle.

The Back-up and Copper fixes can help but may only cover the real problem. Stopping the leaks is a must, But, if you accomplish Leak Stoppage and the problem is Pressure Spikes the next problem will be blown Plumbing or other failures caused by high pressure being released too quickly (INSTANTANEOUSLY) each cycle.

I use a Pressure Gauge of, 2-4 times the operating pressure, plumbed in the cylinder line that has a check valve in series with it. The check valve allows free flow in to the Gauge. After a couple of hours of cycling under normal operating conditions the gauge will be showing a pressure that is near the peak of the spikes if the check valve is of a no leak design.

If the press is one manufactured by a company that is still in business it should have a decompression feature in the circuit. The problem may be one of adjustment of that part of the components.

On some local 2500 Ton presses the Decompression Shock is controlled by some valves buried in the 6,000 Gallon Tank and will reak havoc on Schedule 160 6" Pipe in short order when not correctly adjusted. It takes 5-8 seconds to decompress the 50" Bore Cylinder from 1,700 PSi to low enough pressure, under 500 PSI, preferably under 250 PSI, to elminate Shock. You can hear the press reversing at the end of the pressing cycle a block away when it is signalled to retract too soon.

At least that is something I would look into if you have not already done so. Even when there is no easily detectable Shock noise the circuit still gets damaged, just takes longer.


Bud Trinkel, Fluid Power Consultant
HYDRA-PNEU CONSULTING