need help adjusting relief pressure at spool

memphismark · Jan 13, 2016

Hey guys. Was wondering how to adjust the pressure relief in a Prince 20 gallon open center spool. It's factory set at 1500. Would like to bump it up to 2200-2500 for more torque. Do I need a pressure gauge teed into the line? I'm guessing the line needs to be pressurized? Would appreciate some help.
memphismark

/pine · Jan 13, 2016

What are you supplying it with (GPM) and what is the relief valve on the supply set at?

Yes you need a gauge...tee it into one of the working ports and max out or in whatever cylinder etc, it is attached to...see what the gauge says...move the lug (usually CW to increase the pressure, CCW to decrease) on the PRV until the gauge reads what you want (in accordance with the PRV on the source)...

J_J · Jan 13, 2016

memphismark said:
Hey guys. Was wondering how to adjust the pressure relief in a Prince 20 gallon open center spool. It's factory set at 1500. Would like to bump it up to 2200-2500 for more torque. Do I need a pressure gauge teed into the line? I'm guessing the line needs to be pressurized? Would appreciate some help.
memphismark

Install a 3000 psi hyd gauge in a tee and install it in the IN port of the valve in question.

If the relief valve uses shims, install the shim pkg. Engine off.

Use the valve lever to fully extend the cyl, or retract and read the pressure.

With engine running, and the relief valve is adjustable, monitor the gauge, and turn screw in to increase pressure and out to reduce pressure.

memphismark · Jan 13, 2016

relief is set to 1500 at factory, for about 14 GPM on a concrete mixer. My problem is the only way to put a load on system is to mix concrete. That makes me nervous because clock is ticking with concrete if you know what I mean. Can I just plug the line to 'put a load' on system and then proceed with adjusting? I'm a hydraulics novice so thanks for your response.