LS-3000-1 Log Splitter Pressure Release Detent Question

     Question: On the LS-3000-1, what is the preset PSI and what is it adjustable to on the pressure release detent for the cylinder return?

     Answer: The LS-3000-1 pressure release detent is set to center the handle when the B port reaches a preset 1400 psi.  The inlet relief of the LS-3000-1 log splitter valve is preset at 2250psi @ 3 gpms and 105 degree F.  We recommend 250psi at a minimum between the inlet relief and pressure relief.  You would want your inlet to be 250psi higher than your pressure relief detent.

Below is the engineering spec section for for reference:

     Relief Valve Settings

          Unless otherwise noted with order code or on print, relief valve setting is to be 2250 psi* ± 100 psi @3 GPM ± 1 GPM.  All other settings to have similar ranges unless otherwise noted on assembly drawing or bill of material.

          *The Relief Pressure is defined as the pressure drop from the inlet of valve to the outlet of valve.  3 GPM must be flowing across the relief at 2250 psi.

     
     Detent release pressure to be 1400 psi ± 150 psi at 3 GPM as standard setting.  If the relief setting is less than 1650 psi, the detent release pressure is to be set at the relief setting at minimum minus 250 psi.

Be sure to check out our youtube videos also.

Please visit our LS-3000-1 Catalog pages.

Please visit our LS-3000-1 Parts Manual pages.

Please visit our LS-3000-1 Instruction Sheet pages.

Please visit our LS-3000-1 Availability.

Hydraulic Power Beyond

This is a really good video done by someone with
a Kubota Loader.  Very nice.  Below are some links to the RD5000 2 spool valve
that he is installing.

http://www.princehyd.com/Portals/0/valves/RD5000InstS.pdf

http://www.princehyd.com/Products/Product-Configurators/product/Valve/family/RD5200

http://www.princehyd.com/Portals/0/valves/RD5000Manual.pdf

http://www.princehyd.com/Portals/0/valves/ValvesRD5000.pdf

http://www.princehyd.com/Products/Hydraulic-Valves/Mono-Block/25-Gallon-Two-Spool

Regen Log Splitter - 20 GPM's?

The other day this question came in: Can I use the Prince LSR-3060-3 valve with a single stage 20 gpm pump?  The short answer is, No.

The longer answer is:

A regen circuit can be used to cause a cylinder to advance more rapidly than it could with pump oil flow only.  It can only be used to increase speed in the extension, not in the retract direction.

The basic idea of regen is to connect the rod end of a cylinder to its blind end or extend end, using suitable valving (see LVS, LVT and LVR Loader Valves and LSR Rapid Extend Log Splitter Valve), so the oil which normally would be returned to tank from the rod end will be combined with the pump oil.  This causes the cylinder to extend at an increased speed.  The hydraulic schematic on the bottom of the 2^nd page of this linked pdf shows the regen circuit with in the valve.

Some notes on Regen:

-       In regen, the force produced will be equal to that produced by the pump pressure based on the area of the rod.

-       Regn is usually used with cylinders that have large rods.

-       With larger rods, you need to be aware of pressure intensification.  Some applications require a relief valve on the retract port or rod end of the cylinder to handle the pressure intensification that can happen during extend.  Take for example the LSR-3060-3 Log SplitterValve.  It is going to provide extend flows up to 25 gpm with inlet flows of 4 gpm.  What would happen if you have an inlet flow of 20 gpm?  You would see extend flows attempt up to 120 gpm.  The work ports and hoses are the wrong size to handle 120 gpm.  You would see large pressure intensification.

-       Regen is typically used to get a machine or part of a machine (loader bucket tip, log splitter cylinder) into position or the force needed to perform the work is small.

-       Caution should be exercised when sizing the oil reservoir.  A cylinder with a larger rod will cause the oil in the reservoir to fluctuate more than normal.

So why does a regen circuit work?

            In a regen circuit the same amount of pressure is applied to both sides of the piston in the cylinder.  Working similar to a displacement style cylinder, the larger area (extend side) will cause the cylinder to move – extend.  The retract side or rod side doesn’t have as much area because the rod is taking up space – Force = PSI X sq inch area of rod.

I hope this is useful information for you. 

Slow Loader - Spool Valve Problem

I received the following the other day: I purchased a two-spool control valve RD522GCGASA4B1 on 4/27/11 from xxxxxxxxx.  The unit is mounted on a '65 Ford 3400 with front end loader.  For the last 3 or 4 months the lift cylinders have been going up real slow at 1200 rpm.  If I increase the rpm's to 1800 it goes up a bit faster, but not much.  The lift cylinders are connected to the spool valve next to the relief valve.  The bucket cylinders snap bank and forth real fast with or without a load.  The normal load on the unit is a 900-1000 lb round hay ball.  

The other thing I noticed is that the spool valve for the lift cylinders will go to the bottom and hit a hard spot, then when forced with the handle will continue down and unload the lift cylinders allowing it to fall fast.  Is this normal?

I contacted your distributor they referred me to xxxxxxxx at your plant.

My questions are:  1 - What would cause this problem?   2 - If it is the spool valve can I fix it with new parts?  

These are typically easy issues to get thru depending on how much folks know about their system, sometimes they can get tricky.  The following are my comments:

The RD522GCGA5A4B1 doesn't change the flow rate or generate pressure (it does have a pressure relief cartridge at the inlet).  This valve takes the inlet flow and directs it to either the outlet, or one of the 4 work ports.  In the float position the inlet and work ports are connected to tank.  (http://www.princehyd.com/Products/Hydraulic-Valves/Mono-Block/25-Gallon-Three-Spool will provide details on this valve is a flow directing control valve.)

Cylinder speed or movement speed is determined by the amount of flow that is available.  With a gear style pump, increasing the pump speed or RPM’s will increase the flow rate or cause the cylinders to move faster.  The cylinder bore is another item that can affect cylinder speed.  A large bore cylinder (lets say 6 inch bore) being filled with 10 gpm’s will extend slower than a small bore cylinder (2 inch bore).  This has to do with area.  The 6 inch bore cylinder has more area to fill and is going to fill up slower than the smaller 2 inch bore cylinder.

You mention that shifting the handle in a certain position will cause the loader to fall fast.  This is likely the float option and based on your description, it is working fine.

Here is some information on trouble shooting a hydraulic system.  

Loader Valve Trouble Shooting maybe helpful also. 

Parts Manual for the RD5200 Valve.

With a pressure gauge these types of problems are usually easy to resolve.