Hydraulic Question on Reducing PTO Pressure and Flow

[woodlandfarms]

Yes, the PTO has a relief valve. But it is not a full relief, It will bog the engine and eventually kill it. At least on mine it does not give up much.

Relief is built into the PTO control block.

I assume this was your question.

 

[J_J]

I believe all Pt's have a relief in the PTO circuit. If your relief in not on the solenoid valve itself, it is on a hyd block.

 

[J_J]

You also said something about a closed center something as part of the circuit. The fluid generated by a gear pump for an open center circuit must flow continuously.

A closed center circuit will either hold the pressure at the valve, or unload the pump until the pressure is needed, and a variable speed pump is used.

If the wheel motor is good and tight, it will turn, based on the amount of fluid you provide to it.

If you are wanting a lower pressure downstream, you will need another relief valve set for the particular circuit.

 

[SpringHollow]

Thanks Carl and JJ. I thought it did but it does bog my tractor down too. Like you say, Carl, maybe it is not rated for full flow.

I do remember now talking to Terry about my tractor's PTO circuit one time. Had a bad cartridge in the solenoid valve. He was having me turn on the PTO without anything connected which i always thought you could not do and he said it was ok for a little bit and they used that to help trouble shoot.

I still will keep that 3000 psi one on the circuit, i think. Cheap insurance.

Ken

 

[J_J]

A good way to test the PTO circuit would be to plug a hyd gage into the QD and flip the switch on, and you will read the relief pressure, and can check and set it. If the PTO pump is the only circuit using hyd fluid, you should have enough HP to run the PTO pump.

If you put a 2000 psi relief in the circuit, what will happen is that when the resistance to the fluid in that circuit reaches 2000 psi, it will start dumping and try to maintain pressure at 2000 psi.

What will be using the fluid, a cyl or hyd motor?