Hydraulic Flow Rate

Jfw1023

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Kubota Grand L4060 HSTC
Feb 2, 2024
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Hillsborough NC
I’m trying to figure out the Hydraulic Flow Rate for a Grand L4060 with a Model#L2265 3rd Function Valve Kit installed. More specifically I’m looking to purchase a hydraulic auger and need to know how much flow I have at my 3rd function valve. I know the tractor has a total hydraulic flow rate 14.7. GPM and the hydraulic pump output is 9.8 GPM but I’m not sure if that would be the same at the front connection.

Many Thanks for any responses!
 

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GreensvilleJay

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well according to 3rd PDF specs, it's got 9.8GPM, though no mention as to the pressure( PSI) which is ,um, well, a kinda IMPORTANT spec !!!
 

North Idaho Wolfman

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An L4060 HST does not have 9.8GPM it has 9.4GPM, yea I know small change.

A typical third function will not have anywhere near that for flow to the outputs.
Flow will be based on the valve type and size, port size, line size and PSI.
And a typical Third function is lousy at supporting a hydraulic motor load.
They are not meant to be run for a length of time, doing so will overheat the coil and valve.

@TheOldHokie should be along, he would be the one to give better answers.
 
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Jfw1023

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Kubota Grand L4060 HSTC
Feb 2, 2024
2
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Hillsborough NC
An L4060 HST does not have 9.8GPM it has 9.4GPM, yea I know small change.

A typical third function will not have anywhere near that for flow to the outputs.
Flow will be based on the valve type and size, port size, line size and PSI.
And a typical Third function is lousy at supporting a hydraulic motor load.
They are not meant to be run for a length of time, doing so will overheat the coil and valve.

@TheOldHokie should be along, he would be the one to give better answers.
Okay, thank you very much for the feedback. Makes sense.
 

ken erickson

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@TheOldHokie should be along, he would be the one to give better answers.
I am sure NIW is correct on TheOldHokie giving best answers! I did see this on Summit Hydraulics site and I have no idea how the Landpride 3rd function solenoid valve compares. The Summit valve is listed at 15GPM with a 3000 PSI rating. But they also mention that there are 3 different spools as options. A different spool for operating hydraulic motors compared to double acting cylinders for example.

solenoid-control-valve-d03-tandem-center-waterproof-12v-dc-dt-connection

This is found on their 13GPM third function kit.
hydraulic-third-function-valve-kit-w-joystick-handle-for-tractor-loader-13-gpm

  1. Are you operating a hydraulic cylinder or a hydraulic motor? If you’re operating a hydraulic cylinder you’ll need to get “A” spools for double acting cylinders, if you’re operating a hydraulic motor you’ll need “D” spools for motor control. Note: “D” spools cannot be used for operating hydraulic cylinders and “A” spools cannot be used to operate hydraulic motors.
 
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TheOldHokie

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windyridgefarm.us
An L4060 HST does not have 9.8GPM it has 9.4GPM, yea I know small change.

A typical third function will not have anywhere near that for flow to the outputs.
Flow will be based on the valve type and size, port size, line size and PSI.
And a typical Third function is lousy at supporting a hydraulic motor load.
They are not meant to be run for a length of time, doing so will overheat the coil and valve.

@TheOldHokie should be along, he would be the one to give better answers.
Well since you asked I would expect to get pretty close to the 9.4 GPM rated flow of the pump. I dont see that being the problem.

For a gear pump the flow is basically linear with RPM and does not vary substantially with pressure. Pump flow is going to be the 9.4 GPM claimed.

The flow rating of the valve is the flow it can sustain with a specified pressure drop from inlet to putlet. Different OEMs base their valve ratings on a pressure drop of their choosing but 100 PSI is a typical industry rule of thumb. So for example a valve rated for 13 GPM will exhibit a 100 PSI pressure drop P->T when flowing at 13 GPM. In a directional spool valve pressure drop P->A,B will be a bit higher. A 13 GPM industrial solenoid valve (D03) should not be a problem at 9.4 GPM. If you were to feed it at 15 GPM you would get the flow but the pressure drop across the valve would increase.

Same sizing rule goes for hoses and couplers and thats where problems are most likely to arise. With hoses the longer the hose and/or smaller the diameter the greater the end to end PRESSURE drop. Thats what you want to minimize. All of the pressure drops eat up power and generate heat which is the real enemy.

So returning to the 9.4 GPM tractor and hydraulic motor question. That flow rate is pretty low in the relative scheme of things. The 3/8" hoses and outlets that Kubota favors is OK for low duty cycle loader cylinders but is going to scavenge power and add a lot of heat to the system in a motor application. A better fit there would be 1/2" hose and couplers for motor supply side and most designers would probably want 5/8" hose or larger on return side. If you can go straight to tank on the return line bypassing the return side of the valve and all the internal tractor circuitry you help things out a lot.

Dan
 
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TheOldHokie

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Me thinks JFW didn't get an answer? Will a L4060 run a front mount auger?
I think JFW got a very complete answer to his flow question.

Your question is different and the answer depends on the hydraulic requirements of the auger. Augers come in many different sizes. The L4060 can run smaller ones but many are well beyond the capabilities of a L4060.

Dan
 
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