L**40 rear hydaulic pressure

[J_J]

Would you call that pressure intensification. I had asked about that earlier.

 

[Chilly807]

Would you call that pressure intensification. I had asked about that earlier.

JJ,

I'm not 100% sure what the exact definition of pressure intensification is, but I thought it was the result of passing fluid already under pressure through another "stage" or pumping element to further increase the existing pressure.

An example would be a multi-stage compressor or a series of water pumps.

It might be worth digging around the net to find an actual definition of intensification as it is used hydraulically.

Just as an aside, I thought the technical term for what Lee is describing is "10 pounds of sh*t in a five pound bag" :laughing:, meaning that the displaced volume is being forced into too small a space.

That is one of the reasons I had avoided using a cross-over relief valve on my rear blade cylinder, unless you can dump the excess to the tank it has nowhere to go and the pressure will still increase.

Sean

 

[J_J]

Somewhere I saw a demonstration of intensification, using only one cyl. They only installed a 10,000 pressure gage in the rod end of a cyl, and applied pressure 3000 psi to the base end, and the gage read way above the rated cyl pressure. I believe there was an accident involved.

I believe a meter out situation can cause pressure intensification by restricting the out flow in a cyl.

Here is a video to demonstrate this.

Pressure intensification caused by meter-out flow control

 

[dfkrug]

I believe a meter out situation can cause pressure intensification by restricting the out flow in a cyl.

Here is a video to demonstrate this.

That's an interesting simulation video. It shows how the pressure
rises in the rod side of the cylinder when out flow is restricted. I
experimented a bit with that when I was testing flow restrictors in one
of my hydraulic thumbs.

This is a dynamic case, however, and that pressure will drop to zero
when the piston reaches the end of its travel. The OP has tested
his AUX pressures in the static state with no cylinders, a "deadheaded"
case.

 

[oldnslo]

Pressure intensification via single rod cylinders.

Example: 2 1/2" bore x 1 3/8" rod

2 1/2" bore = 4.9 square inch area
1 3/8" rod = 1.48 square inch area

4.9 - 1.48 = 3.42 square inch area which is the rod end area of the cylinder.

Using equation of Force = area x pressure.

2000 PSI x 4.9 = 9800 lbs of force.

9800/3.42 = 2865.5 PSI on the rod end if that port is blocked..

This does NOT allow for the weight of the loader but it does represent cylinder intensification.

Hope this makes sense.

Roy

Hey Kubo, can't explain what or how but yes reliefs can fail. Typically they are designed to fail open though. Glad things are working and do NOT check it again


Without having the valve casting in front of me I can't even speculate how the RV would fail on the RR and not the FEL.

 

[kuboman]

Hey Kubo, can't explain what or how but yes reliefs can fail. Typically they are designed to fail open though. Glad things are working and do NOT check it again


Without having the valve casting in front of me I can't even speculate how the RV would fail on the RR and not the FEL.

I may just throw the gauges in the dumpster and remain ignorant. Life seems simpler that way.:laughing::laughing:

 

[Leejohn]

4shorts
I checked all the pages you posted and if you wouldn't mind would you scan page 8-M15 of the manual and post it.
I can't do it, my printed went belly up. That page shows the up system and what is going on can be seen on that page.

Thanks, Lee

 

[J_J]

kuboman,

I would suggest mounting one of those gages before the FEL, to monitor and trouble shoot the hyd system.

You could cut your pressure line and do something like this for a pressure gage extension. Just use a tee at the union and run a line up to where you can see the gage while operating the tractor.

 

[dolphins65]

Get the dealer/agent to fix the bloody thing. Too dangerous to F#^* about with girls'n'boys. Face it ,ya dunno what ya duin'...

 

[4shorts]

4shorts
I checked all the pages you posted and if you wouldn't mind would you scan page 8-M15 of the manual and post it.
I can't do it, my printed went belly up. That page shows the up system and what is going on can be seen on that page.

Thanks, Lee

Hey Lee. Sorry I missed your post. I only just noticed it. Do you still need that scan? Sorry about that.

Paul