Hydraulic tubing question

[Henro]

I am in the planning/learning stage that I hope will lead to my having a T&T setup on my Kubota B2910 before the snow falls again... /forums/images/graemlins/blush.gif ... I guess my age/experience is showing...there was a time I would have said "before the cherry blossoms fall off the trees..." /forums/images/graemlins/smile.gif

Anyway, I see mostly fittings and hoses used by guys here at TBN, but have not seen much mention of tubing being used. I also have not noticed many tubing fittings being sold. Now I know they are probably on every page of every catalog and I am just too dumb to see them because they are not jumping off the page into my face... /forums/images/graemlins/tongue.gif

So my question is how hard is hydraulic tubing to work with? I remember some years ago replacing a brake line on an old van I had and it was a simple matter to bend the line as needed with a hand tubing bender.

It just seems like a mix of tubing and hose, like is in place on most loaders I have seen, could be a nice way to go with a homebrew T&T installation.

I guess my questions are:

Is the tubing used on 2500 PSI hydraulic systems easy to work with? Is a simple hand tubing bender all that one needs to work with this stuff? I suppose some kind of mild steel tubing would be easier to work with than stainless, but that stainless tubing might be better in the long run...I don't have a clue as to whether stainless tubing can be hand bent or not.

What kind of fittings would be recommended for metal tubing? Flare? Compression? Something else?

I know it can all be done with hose. On the other hand, I wonder if anyone might have any pictures of how they did it using tubing as part of their system...

Any advice would be appreciated! Even if it is "forget the tubing..." /forums/images/graemlins/smile.gif

Total novice here with respect to hydraulic projects so any advice will be helpful.

 

[JerryG]

I think that you would be very limited in the use of tubing for a TNT. Hoses are used because of the flex that they allow.

 

[40Kchicks]

Henro

I’m not sure where you would use tubing for a TNT. I would think the ideal setup would be hose with swivel JIC connectors.

Eric

 

[ronjhall]

Henro ...aka Bill

Many years ago I did some tube bending for industrial hydraulic systems. It's an art that can be learned.
Here is a link to Swagelok. They have a PDF manual on bending tubing.

Hoses is easier to make and install on a tractor when doing upgrades.

Tubes require precise bending to get through the frame and around parts of the tractor.

Hydraulic tubes cannot be touching each other. They will soon wear a hole into each other. They require special supports like you see on your loader tubes.

In a production system like Kubota has for building FEL’s it is easier to install a set of pre made tubes instead of running hoses.

I still have the tools to do 1/4 and 3/8" tubing. But have not done bending or flaring in 20 years. /forums/images/graemlins/tongue.gif

When I install an autopilot in my boat I used high-pressure plastic tubing. The pressure is not as high as a tractor.

 

[Henro]

Ron I will check out that manual on tube bending....thank you for the link. And thanks to everyone else who responded. /forums/images/graemlins/smile.gif

One of the things I was thinking of was how I would mount lock valves if I wanted to use them. I know I could get a top cylinder with a lock valve mounted on it from CCM, for example, but for the tilt side I have not seen a cylinder short enough that had a lock valve attached to it. It looks like the lock valve on the CCM cylinder is piped with hard tubing on the valve side. I was thinking if I mounted lock valves(s) on the tractor I might be better off with tubing between the lock valves and the control valve.

On top of that I am thinking that I might as well add a couple extra control valves to the stack, if I am going to the trouble of doing it myself anyway. What I am thinking is to use a prince stackable valve, and to build it with five sections. So if I did this I would have 20 pieces of hose, 10 of which would be between the control valves and lock valves...

I am thinking of putting a tilt cylinder on each side. The reason for this is because I could then maintain the same geometry of the existing 3PH and lift (or lower) both sides all the way and know the implement is level. That would take up three positions out of five...

Like I said, I am in the learning process. I am not sure I will use any tubing at all. I do see some possible advantages, but also see the limitations.

I do appreciate the advice! If anyone has anthing else to add, please do!

 

[Glenn9643]

One of the problems with my tilt cylinder is too much flow, especially at PTO rpm, causes it to be very quick to respond to adjustments. I still haven't added flow restrictors and it's hard to adjust without jerking at high rpm's. Right after I got it I was bushhogging and needed to make an adjustment as the cylinder won't hold a load very long. It jerked up too high, and when I tried to adjust it back down to level it jerked too far down and lifted the right tractor wheel. From that experience, if you had tilt cylinders on each side you might could get some down pressure for box blading, etc. It might also put stresses on the tractor that it wasn't designed for???
The POS tilt cylinder is about 1-1/2" too long when retracted to be level with the fixed side and has caused me too much aggravation with leaking down under a load. I'm now thinking of buying a new larger bore cylinder from Prince or some such place and welding the ends from this one to it to make a new one that will be level when retracted and hopefully won't leak down as bad. I've had good results with the top link cylinder I got from Prince.

 

[MadReferee]

Henro,

The Prince SV valve can be configured with many different spools. One of them has pilot operated checks on both work ports. Part number is SVL1CA1, 4 way with spring return to center and check valves. I don't have any info on the specs for this spool but I am sure you can get info from Prince.

If you go to the Prince web site and download the PDF specs for the Directional Control Valves, the SV stuff will start on page 45.

Also you can get the tilt cylinder with checks for the B2910 (their ends are removable) from Integration Engineering. Cost is about $275 delivered. Jim McC told me mine will be shipping this monday and I should have it later in the week. I'll post pics in my TNT thread. Jim can also supply line restrictors which will help you with feathering the valve. I used 1/4" hose for the work ports and it helps too.

 

[Egon]

Henro:

Stainless steel tubing bends quite easily with a hand bender. The flared ends for that pressure require a different flaring method than what you use on copper pipe. The compression fittings, swagelock, are very easy to install and come in a plethora of styles. Be sitting down when you price them out.

I'd suggest the hose with quick couplers would be much easier.

Egon

 

[Inspector507]

Henro
If what you were looking for is a tilt cylinder with a pilot check valve, Jim at Integration Engineering has one. I attached a link to the picture of it.

 

[PineRidge]

Henro make sure that you do get the restrictor for your cylinder. Mine were not sent at the same time as the cylinders and caused me some grief because of response that was way too abrupt. Once I added a set of restrictors the top & tilt settled down and could be adjusted without being too abrupt in operation.