steal line rupture

[txdon]

Billycalexander, thanks for sharing. I wonder if this also happens on other brands of tractors as well. Maybe there needs to be some kind of pressure relief valve when the joystick is in the neutral position.

 

[jinman]

</font><font color="blue" class="small">( Maybe there needs to be some kind of pressure relief valve when the joystick is in the neutral position. )</font>

A steel tubing rupture has happened to bgott in the NH forums and I have blown four hoses on my NH. Rupturing steel tubing is probably pretty rare. I'm just glad yours didn't let go when you were trying to lift Lucy.

I think the thing about a relief valve is it would need to be set pretty high, somewhere around 6000 to 8000 psi. As RaT noted earlier, his 5000 psi gage pegs easily on his tractor. I guess you could set your relief at 1-1/2 to 2 times the normal maximum pressure. What do you have in mind, Don?

 

[txdon]

<font color="blue"> "What do you have in mind" </font>

Jim I was thinking that maybe the valve could be redesigned so that when the pressure is put on the bucket by driving forward the pressure could be released even if the joystick was in the neutral position. I don't know what the negative ramifications would be, but it's got to be better than system failure.

Or, there could be an in-line 5,000 psi relief valve on each line that fits at the hose to steel connection.

 

[jinman]

</font><font color="blue" class="small">( Or, there could be an in-line 5,000 psi relief valve on each line that fits at the hose to steel connection. )</font>

Don, I believe the relief only needs to be in the bucket's curl-up side. When you are back dragging with the bucket, hitting an obstacle would most often just lift the front of the tractor. When going forward with the bucket curled down, I think you are most likely to find high pressure spikes from hitting roots, rocks, or stumps. (I have had two hydraulic showers from hitting stumps. /forums/images/graemlins/crazy.gif) If I had one pressure relief valve, I'd want it in the curl-up side.

I have been looking at hose for my grapple. I believe the 1/4", 5000 psi hose has a burst pressure up around 14,000 psi. Do you think we generate pressures anywhere near that high? Bailey has a 5000 psi pressure gage on sale right now for $8.95. I may just get one and set it up with quick connect fittings so I can install it inline with the loader.

I also checked to see if they have a relief valve that could be installed. The problem is they only have relief valves that go up to 3000 psi. A higher pressure relief valve may be a special order item and cost big $$$. The relief valves with 3/8" fittings are 1500 psi maximum. To get 3000 psi, you have to go up to 3/4" fittings. 1/2" fittings top out at 2500 psi. So we may be able to discuss this issue, but putting it into our systems could be an expensive plumbing nightmare. /forums/images/graemlins/frown.gif