Belt driven Hydraulic Pump, manufacturer and specs needed.

[wdchyd]

Is it just me, or does that tank size shout 'not for continuous use'?

Depending on number of cyls to supply I'd hope to have room for a bigger reservoir.

Yes, good call. 2 gals is not much.

 

[aczlan]

True, been going back and forth on how to build this. OEM tank was smaller (1 gallon?).
Have a 5 gallon boat gas tank that I could use, kind of wanting this to be an easily portable which would lean towards a smaller (6-7HP) motor, running the pump at the "stock" 6GPM/1500PSI, etc vs being able to run this pump at full capacity and speed (17HP engine, bigger tank, etc) vs just making the backhoe a 3 point backhoe.

Leaning toward splitting the difference, finding a 8-10HP engine and setting it up for 7GPM, 2000PSI and throttling down as needed.
Any thoughts on the flow capacity of the valves, or would I need better pictures/more data.

Aaron Z

 

[RickB]

Control valves need to be rated to handle your pump's maximum flow.

 

[aczlan]

Control valves need to be rated to handle your pump's maximum flow.

Very true, in this case I can change the pump's maximum flow by changing the pulley on the motor.

If I put a 3" pulley on the motor and set the throttle stop at 3000RPM, I will have a pump that will max out at 6GPM.
Set the pressure relief on the valve at 1500PSI and I only need 6HP to run it.

If I put a 6" pulley on the motor and set the throttle stop at 3600RPM, I will have a pump that will max out at about 13GPM.
Set the pressure relief at 3000PSI and I will need a 22HP motor to run it.

If the valve will handle 8GPM, I am now leaning toward skipping the powerpack all together, setting it up to mount on the 3 point of the L3830 and running it off of the tractor hydraulics.

Hence why I am asking how much flow the valve should be good for.

Aaron Z

 

[the old grind]

Port & spool size? IIRC 6 gpm is ok with SAE 6 or 8 ports but 12gpm seems to use min SAE 8 or 10. (clarification?)

That's why plumbing for a FEL diverter can get into a lot of specific fittings/adapters, swivel & 45 or 90 degree, etc for ease of installation and service access.

Front & rear 'kits' include brackets & sort out the hose bits/ends for us. If one has more bucks than time ...

btw, happiness is having a Parker store ten minutes away. Not everyone has that convenience.

 

[wdchyd]

“The maximum flow rate required to flow through a valve is not always equal to pump flow. When a cylinder retracts, the flow discharging from the blind end of the cylinder can be much higher than the flow entering the rod end. This means that a cylinder with a large diameter piston rod, retracting at full pump flow, can be trying to push as much as twice the pump flow rate through the directional valve.”
( Sizing Hydraulic Valves )

Valve rating should be the max flow it sees through the core, not just pump max flow.

 

[RickB]

“The maximum flow rate required to flow through a valve is not always equal to pump flow. When a cylinder retracts, the flow discharging from the blind end of the cylinder can be much higher than the flow entering the rod end. This means that a cylinder with a large diameter piston rod, retracting at full pump flow, can be trying to push as much as twice the pump flow rate through the directional valve.”
( Sizing Hydraulic Valves )

Valve rating should be the max flow it sees through the core, not just pump max flow.

Which is part of why many valves have larger return ports than pressure ports. In the real world, open center valves can be sized on max pump flow because that flow can be continuous and accommodating that flow is critical to keeping oil temps in check. Calculating intermittent return flow surges is only worthwhile in the most obscure cases. Even in continuous duty that return flow surge only happens a bit over 50% of the time. I've yet to have a valve retailer ask for return flow numbers when sizing a valve. Has anyone?

 

[wdchyd]

...........I've yet to have a valve retailer ask for return flow numbers when sizing a valve. Has anyone?

No, but I had several successful troubleshooting jobs that were designed by others, engine was bogging down on cyl retract (not on extend)......and the issue was a valve rating only matching the pump outflow and not large enough to accommodate the extra flow from return.
Return flow still flows thru the core, not just the out ports.

 

[RickB]

Return flow still flows thru the core, not just the out ports.

No argument there. But very very few people are gonna calculate that surge flow. I'm not aware of any manufacturer that mentions it in any spec sheet or valve sizing guide. And odds that doing so will make a difference are very low. Otherwise you would not be the only person to ever mention it here.
Like a lot of things, going through the exercise can't do any harm and there's a small chance it could be beneficial when a valve is marginally sized to begin with and the cylinder rod/cylinder bore ratio is high

 

[wdchyd]

.......I'm not aware of any manufacturer that mentions it in any spec sheet or valve sizing guide.......

Maybe you missed my link in post#16?