FEL and Rear T&T Control Valve Flow Capacity Questions

[TX mower]

.... I would offer an opinion, I do Not generally employ stand alone restrictor values.

If I need precision feathering, it is usually for a hyd motor and Use of a valve w/ built in flow control does the trick.
Example : Brand Hydraulics, surplus center product # 9-7497-30 ......

Fair enough. Though presented only as an example while that particular control valve might offer superb control it won't work for my application given lack open-enter PBY capability and cost. And I while do understand your point about what can be achieved by a skilled operator with specialized purpose-built equipment, that's not the 'market' this consumer is dealing in.

I'm looking to fill a need that will accept some compromises (other than safety and reliability) in recognition of my practical duty-cycle and budget. Input provided here, including yours, is helping me get closer to a 'best balance solution' for my situation, so that's much appreciated.

...... I equate restrictor valves to training wheels on a bicycle.

Elegantly functional, KISS, and serving a great purpose, those training wheels
_____

As far as SC and customer support, I do understand all of your points. Perhaps worth noting that in my email correspondence I included my phone contact and invited response by phone if more efficient for them. For me, when a vendor explicitly invites a means of getting info and then doesn't respond at all that reflects (negatively) on their business and does factor into my buying decisions, especially when talking about a commodity that's competitively available from other sources which are responsive to nimrod / small quantity purchasers. Obviously that's a personal choice in the competitive market. I'm quite sure that SC recognizes that and willingly accepts the small loss of market that goes with their choices, no worries.

 

[majorwager]

TX,

Think you have a greater grasp of fluid mechanics than you admit, a compliment not criticism. I don't cheerlead for SC, they simply fill a purchasing void for my projects. I claim no expertise, much trial and ERROR experiences.

Good luck in your quest, you are well on your way toward solutions.

 

[CincyFlyer]

I'm one of the people with the "giant" 25 gph valve, it also has a lever twice as long as the stock valve. Feathering is as good as the original, period. Come on over and try it.
The 'old' valve will serve as a T&T (or whatever I want to hook to the rear.) I haven't built cylinders for T&T yet, but restrictors at the T&T cylinders are pretty much required, and are commonly used.
It ain't rocket surgery.

 

[TX mower]

major,

Fluid mechanics isn't foreign to my engineering background, just not at the scale and with the specific types of controls I'm now learning about in the ag tractor context.

And capitalizing on the real-world trial-and-error experience of others is exactly the benefit of resources like this forum .... I do very much appreciate everyone's contributions in that regard :thumbsup:

 

[majorwager]

Not familiar w/ rocket surgery, that might be more prevalent in N Korea?

Using a 25 gpm valve on a small output tractor certainly would necessitate flow restriction. Everyone has a different approach to their solution.

It is unlikely a fluid mechanics engineer would support a gross mismatch of output vs capacity but what really matters is that it functions properly for your application.

The flow restrictors vs training wheels analogy is an opinion, one of many on T-B-N, and not a solicitation for unanimous consensus.

 

[TX mower]

So, considering all the input and research, here's where I'm inclined at this moment (which is actually a return to an early notion about the project) .....

For T&T control, install another of the 10GPM Brand Hydraulic LV22RFSTKAB joystick control valve with PBY like I recently installed for my FEL.

• Using 'boom ports' it'll provide top-link float which I think I may use fairly frequently
• Using 'bucket ports' it won't provide tilt-float which I think won't be too much of a compromise (I could swap top and tilt hose ports at the rear quick-disconnect panel if I needed tilt float for a particular project)
• From inspection of the valve I now have I know how to easily modify it to 'block-out' the bucket 4th-position rapid-regin which won't be used on the tilt cylinder in this application
• It's very compact which is of benefit in my application, lends well to a good mounting position on my Yanmar, and the single stick for controlling two spools is attractive to me.
• It's cost effective in comparison to the 2-stick* 2-spool solutions offering similar controls (noting those are all 14 GPM nominal flow which may be a relative slight disadvantage for those 2-stick solutions).
• IF, after using it for awhile I find the cylinder control is too 'twitchy', add simple inline flow restrictors as needed.

Then, if I later modify my Box Blade to add a hydraulic cylinder for actuating the ripper-teeth drop/raise (they're on a manual lever-operated pivot-bar on my box), or get a side-shifting flail mower, add a simple and inexpensive single-spool DA valve in the series for that function.

Gonna cogitate on it a bit more but that's the current inclination ... this isn't an immediate need rush project for me.

Continued input welcome.

* yes, several of the 2-stick 2-spool solutions can be converted to single joystick operation, at additional cost.

 

[MtnViewRanch]

TX,

Your question to fallon, believe you made a proper assumption. Heat, cavitation not likely. I equate restrictor valves to training wheels on a bicycle.

I feel that restrictor valves make life a lot easier. Why fight constantly feathering your control valve when there simply is no need to do so. Everyone does not have thousands of hours of experience using these things and another thing, all valves do not feather well. Everyone does not have an industrial machine or even a higher dollar piece of equipment.

Again, why make life difficult when it is so easy to make things simpler? :confused3:

 

[CincyFlyer]

Not familiar w/ rocket surgery, that might be more prevalent in N Korea?

Using a 25 gpm valve on a small output tractor certainly would necessitate flow restriction. Everyone has a different approach to their solution.

It is unlikely a fluid mechanics engineer would support a gross mismatch of output vs capacity but what really matters is that it functions properly for your application.

The flow restrictors vs training wheels analogy is an opinion, one of many on T-B-N, and not a solicitation for unanimous consensus.

You misunderstand. The 25 GPM valve has no restrictions, and I can easily feather it, contrary to a report from someone who does not have one. It works as well as the "matched" factory valve. Note that how sensitive a valve may be and the flow rate are only distantly related.
The restriction for the T&T makes sense; you can limit the absolute speed of operation, which is a good thing for a T&T setup.

 

[majorwager]

TX,
If it isn't difficult, why do it? Attempted humor.

I like Brand products. This valve has the float function on one spool, correct ? I am not familiar w/ forth function circuit? Is that similar to a " "return to dig" position? Or a raise/curl combo option? I have only owned three function valves. I did notice the relief pressure might be preset to 4000 psi. Too high for a compact. It should be adjustable? Your application may not ever exceed tractor pump psi but I would reset it to my pump max.psi.

Will you just connect a short loop for 4th function? I prefer not to dead stop any valve settings even though engagement would be momentary.

I use the tractor factory remote for my top link, have no use for a tilt cylinder. My top link used primarily in finish mower adjustment for varying cutting heights and the mowers all have a flex joint on the top link connection which serves as a float. Kubota only offers remote float valves on 2nd position remote which is absent in mine. Kubota rear remotes are $550. Bare valve, no labor!. Not much ground engagement here, happily those projects long finished. But when I did use my backblade, generally did not float, usually some constant down pressure.

As an aside, spoke to a marketing rep at Brand once during a project. He was so helpful, seemed like he was going to reach right through the phone line and start turning wrenches.

Looks like this project is shaping up, as stated, my expertise is limited, so I have little more input to offer other than to wish you good fortune in developing this project.

 

[majorwager]

Cinncy,
Honestly, I am happy for you, glad it functions. We don't agree on "distantly related" and I do Not own one, that is very true.

So the matter doesn't really warrant further discussion, we can each go in separate directions. Neither worse for the exchange.

A bumblebee defies gravity, yet they fly, so there ya go.....